# LINKEDALU METAL — full technical text

=== Architectural Aluminum (https://www.linkedalu.com/products/architectural-aluminum) ===
LINKEDALU METAL extrudes architectural aluminum profiles for building envelopes, balconies, sunshade systems and outdoor living structures. We work in 6063-T5 and 6061-T6, with 6005A-T6 for higher-strength structural members, and supply mill finish, anodized, powder coated and PVDF finishes to GB/T 5237 or EN 755 tolerances. Wall thickness and cross-section are produced to your shop drawings, with thermal break pockets and glazing or gasket grooves cut into the die so frames assemble without secondary rework. Our press range covers profiles from 0.8 mm to 6.0 mm wall and up to 300 mm circumscribed circle, cut to 6 m random lengths or pre-cut to installation length. In-house fabrication adds CNC machining, drilling, tapping, punching, miter cutting, notching and assembly, so buyers can order finished frames instead of raw sticks. Typical customers are curtain wall contractors, railing fabricators, louver and sunshade manufacturers and modular builders, ordering mixed loads of profiles and machined parts on one shipment.

=== CNC Machining Parts (https://www.linkedalu.com/products/cnc-machining-parts) ===
LINKEDALU METAL machines aluminum components from bar, plate and our own extrusion, so parts can be produced either as standalone CNC work or as finished assemblies built on a profile we supply. We run 3-, 4- and 5-axis CNC centers with turning capacity for brackets, heatsink bases, motor components, housings, adapters, instrument frames and mounting hardware, holding tolerances to plus or minus 0.05 mm on critical features. Materials are typically 6061-T6 and 7075 for strength, with 6063 and 6005A used where an extruded section already provides the shape. Secondary operations include deburring, tapping, countersinking, thread milling, laser marking and surface treatment such as clear or color anodizing, chromate conversion and powder coating. Work is quoted from STEP, IGES or 2D drawings, first articles are checked before series production, and material certificates for bar and plate stock are available on request. Order sizes range from a few prototypes to several thousand repeat parts per year.

=== Industrial Aluminum (https://www.linkedalu.com/products/industrial-aluminum) ===
Industrial aluminum is where extrusion does more than frame a building. This range covers functional profiles for thermal management, electrical machines, lighting, automation, solar energy, temporary structures and vehicle bodies, all produced on the same press line and to the same tolerances as our architectural work. Common alloys are 6063-T5 for extrusion quality and finish, 6061-T6 for machined and load-bearing sections, and 6005A-T6 where profiles are welded into larger structures. Because these parts usually meet another component, we machine what we extrude: face milling for flatness, boring to H7, drilling and tapping, slot cutting, precision cutting to length and deburring. Finishes include clear and black anodizing, powder coating and chromate, chosen for emissivity, wear or appearance. Buyers range from LED fixture makers and motor producers to automation integrators and tent manufacturers, and many order a mix of profiles, machined parts and hardware on a single shipment.

=== Standard Aluminum Shapes (https://www.linkedalu.com/products/standard-aluminum) ===
Standard aluminum shapes are the workhorse sections: angles, round, square and rectangular tubes, T and I-beam sections and U-channels held to consistent dimensions so they can be used without custom extrusion tooling. All are produced in 6063-T5 for architectural, framing and general fabrication work, with 6061-T6 available where higher strength or machining is needed, and tolerances to GB/T 5237 or EN 755. Sizes span small trim sections up to 200 mm sections for structural use, in mill finish and in anodized, powder coated or PVDF finishes for exterior service. We cut to length, miter, notch, drill and tap, so shapes arrive ready to assemble rather than as random stock. Typical uses are railings, sign frames, machine frames, shelving, trailers, solar mounts and general fabrication, with mixed size orders consolidated into one shipment.

=== Furniture and Cabinet Aluminum Profiles ===
URL: https://www.linkedalu.com/products/industrial-aluminum/furniture-cabinet-aluminum-profiles/furniture-cabinet-wardrobe-profiles.html
Summary: Cabinet door frames, handleless gola sections, sliding wardrobe tracks and trim, extruded in 6063, 6463, 6061 and 6082 from 0.8 mm wall, anodized AA10/AA15 in-house, 500 kg per profile.
- Alloy and temper: 6063, 6061, 6463, 6082 - T4 / T5 / T6; other alloys and tempers quoted on request
- Wall thickness: from 0.8 mm
- Maximum section: 540 mm circumscribed circle
- Groove tolerance: +/-0.1 mm
- Dimensional standard: GB/T 5237 high precision; EN 755 / ASTM B221 on request
- Finish: Anodized AA10 / AA15 in silver, champagne, bronze, black, gold; powder coating to RAL; mill finish
- Length: Cut to your cut list - 20' container up to 5.85 m, 40' 6.0 m (two lengths)
- Machining: Sawing, drilling, milling, tapping and mitre cutting in-house
- MOQ: 500 kg per profile, new die or existing
- Trade terms: FOB Shenzhen / Guangzhou
LinkedAlu extrudes furniture profiles on 26 presses from 500 to 5,000 MT, in walls from 0.8 mm and up to a 540 mm circumscribed circle. That spread matters more in furniture than in most extrusion work: a 20 mm glass-door bead and a 120 mm wardrobe jamb can sit on the same purchase order. Alloys are 6063, 6061, 6463 and 6082 in T4, T5 or T6, grooves are held to ±0.1 mm, anodizing runs AA10 and AA15, and the minimum order is 500 kg per profile whether the die already exists or not. Extrusion, anodizing, sawing and CNC machining all happen in the same plant in Foshan, and profiles ship FOB Shenzhen or Guangzhou, cut to your list. Most complaints about aluminium furniture are not extrusion faults. They are drawing faults: a groove toleranced like a window frame, a hinge screw that lands in a 0.9 mm wall, a finish chosen without checking what 15 µm of anodizing does to a push fit. This page is about catching those before the die is cut. What we extrude for furniture Furniture profiles are a family, not a shape. Six of them cover most of the work, and each one fails in its own place. Profile family What the section has to do What belongs on the drawing Cabinet door frames, panel Hold an 18 mm board in a groove, stay flat over the door height, take hinge screws Groove width and depth, groove position from the hinge face, mitre or crimped corner, hinge hole pattern Glass door frames Trap 4–6 mm glass in a gasket without rattling, keep the sightline narrow Glass thickness, gasket type, rebate depth, sightline width, corner joint Handleless (gola / J) profiles Form a finger recess of consistent depth across a run of doors Panel thickness (16, 18 or 19 mm), recess depth, fixing method, end cap Sliding wardrobe frames and track Carry door weight on rollers without sway or rattle, keep two leaves in one plane Roller model, track section, door weight, overlap, bottom guide Carcass, legs and structural sections Carry load without buckling, accept feet, castors or levellers Load and span, fixing points, foot or insert interface Trims, edge profiles and skirting Cover a cut edge or a gap, hold colour against adjoining profiles Panel thickness, reveal, colour reference The alloy decides the face. It does not decide the stiffness. 6063 is the default for anything with a visible face. It extrudes thin, complex sections at speed, anodizes evenly, and most furniture drawings already specify it. The mechanical differences between the two are set out in our 6063 versus 6061 comparison; for furniture, the practical point is that 6063 gives the cleanest anodized face at the lowest extrusion cost. 6463 is the one most suppliers do not offer and most designers do not ask for. It is the bright-dip anodizing grade: iron and other impurities are held tighter than in 6063, so a clear or bright anodized face comes out clean instead of hazy grey. If the profile is a visible handle, a frame trim or a mirror surround, where the metal itself is the finish, 6463 is what decides whether the part looks expensive or looks like hardware. 6061 and 6082 go where the profile carries load rather than looks: table legs, bench frames, brackets, structural rails. Both are considerably stronger than 6063 in T6 and both anodize duller. 6061 machines more cleanly; 6082 is the grade most European structural drawings name. Do not put either on visible trim unless the trim is also structural. Temper is a separate decision. T5 for thin decorative sections that have to stay straight; T6 where the section is doing work and a little straightening is acceptable; T4 where the part is bent or formed after extrusion. Other tempers are quoted on request, and any alloy outside 6063, 6061, 6082 and 6463 goes to the die and press before we quote. Here is the part that changes decisions. 6063 and 6061 have almost the same elastic modulus, around 69 GPa, so changing alloy barely moves deflection. A shelf that sags in 6063 still sags in 6061. What governs sag is span and section depth: for the same load and the same profile, doubling the span multiplies deflection by eight under a centre point load and by sixteen under a uniform load. Shortening a wardrobe shelf by a third does more than any alloy change, and it costs nothing. The same geometry argument is why a 40 × 80 section laid flat is not a heavier 40 × 40: stood on edge, it is roughly eight times stiffer in the direction that matters. Wall thickness: 0.8 mm is a capability, not a specification 0.8 mm is the thinnest wall we run. At that thickness the limiting factor stops being strength and becomes screw purchase, dent resistance, and whether the profile arrives straight after packing. Furniture sections that fail in service usually fail at one of five places, and none of them is the extrusion itself. Where it fails Why What to change on the drawing Hinge screws in a hollow frame A 0.9–1.0 mm wall gives two or three threads; the screw works loose after a season of use Add an internal web at the hinge line, or specify a machine screw into a boss or insert Groove for an 18 mm panel Too wide and the panel rattles; too tight and it will not enter after anodizing Give groove width with a tolerance, and state whether the panel size is nominal or measured Sliding door track Sway and rattle come from roller-to-track fit, not from wall thickness Specify the track and the roller as a pair, with the door weight Long horizontal rail Sag is span and depth; a thicker wall adds weight and cost without fixing it Increase section depth or add a centre support Mitre corners Gaps come from cut length and squareness, not from the section tolerance Put cut length tolerance and squareness on the drawing Tolerance: ±0.1 mm on the groove, and where precision costs you money Groove width and position are held to ±0.1 mm. Everything else is made to GB/T 5237 high precision as standard, or to EN 755 or ASTM B221 where the drawing names them, and noted on the mill certificate. What costs money is not the standard. It is the number of dimensions you tighten. Every dimension pushed below the high-precision table slows the press, adds straightening and raises scrap, and that cost lands in the per-kilogram price whether or not the dimension matters in assembly. Mark the two or three dimensions that decide whether the door closes: usually groove width, groove position from a datum face, cut length, and squareness at the mitre. Leave the rest at standard. Finish moves fits, and this is where furniture drawings go wrong most often. AA15 anodizing puts about 15 µm on every face, so an 18 mm groove closes by roughly 0.03 mm. A 70 µm powder coat closes the same groove by about 0.14 mm. If the panel was a push fit before finishing, it is an interference fit after. Decide the fit after finishing and write that on the drawing. Panels move as well. An 18 mm MDF door is rarely 18.00 mm, and it swells on the humid side of a coastal climate. Tolerance the groove against the measured panel, not the nominal one. Finish: anodizing for the face you touch, powder for the colour you cannot anodize Anodizing at AA10 or AA15 is the finish for visible faces. It keeps the metal reading as metal and it does not chip at a mitre the way a coating does. Standard colours are silver, champagne, bronze, black and gold; other colours are quoted on request. Black anodized shows handling marks and fingerprints more than any other colour, and gloss black more than matte. Worth knowing before a showroom sample is signed off. The wider trade-offs between anodizing, powder coating and PVDF are covered in surface finishes compared. Powder coating is for colour ranges anodizing cannot reach, and for parts where the surface has to hide fine die lines. It builds 60–80 µm, which is exactly why it changes sliding fits, and it chips at sharp corners, so agree a touch-up plan for site assembly. PVDF is rarely specified on furniture because of cost; we quote it when a project asks for it. Consistency between batches is the quieter problem. Dye concentration, bath temperature and the alloy batch all move colour. Agree a ΔE limit and a sealed master sample before the first production run, keep the sample, and book reorders against the same anodizing batch where quantity allows. Without a master sample, "black" is an opinion. Order mechanics: 500 kg, one die, one cut list The minimum is 500 kg per profile, whether the die is new or existing. That is a real threshold for furniture: it lets you run a pilot across five or six sections and test assembly before committing to a container of one profile. Die tooling is quoted per project rather than published, because the cost follows section complexity and the press it runs on. Ask for tooling as its own line in the quotation, with die ownership, storage and what happens to the die if you move supplier. Getting that in writing before you pay is worth more than a discount on the first order. There is no standard length. Profiles are cut to your cut list, which is why the cut list matters as much as the section drawing. A 20' container takes up to 5.85 m; a 40' takes 6.0 m and can carry two lengths. Cuts under 5 m carry a sawing charge, because short pieces mean more set-ups and more offcut. Packing is specified per order: protection film, interleaving between profiles, end caps, and bundle labels that match the packing list. Damage on anodized faces is almost always a packing decision taken to save a few dollars, and it is a claim that is hard to win once the container is opened at the far end. Terms are FOB Shenzhen or Guangzhou. Payment is 30% deposit and 70% against copy B/L or before shipment, by T/T; small orders shipped EXW are settled in full before dispatch. Quality feedback is expected within 10 days of receipt, and claims are checked against the mill certificate and the approved drawing before anything else. Lead time is quoted per order, because it depends on whether the die exists and how the anodizing line is loaded that week. We would rather give you a date we can hold than a standard number that slips. What arrives with the shipment Every order ships with a mill test certificate to GB/T 5237, or to EN 755 or ASTM B221 where the order names them, a dimensional report on the critical dimensions of your drawing, and the anodizing class actually run. The plant holds ISO 9001:2015 and ISO 14001. If your customer audits the project, ask for a pre-production sample signed against the drawing before the batch runs, plus a first-article report on groove width and cut length. It costs less than sorting a container. What to send us Six things get a furniture profile quoted properly: the section drawing as DXF, DWG or a dimensioned PDF; the alloy and temper, or the job the part has to do; the two or three dimensions that decide assembly; the finish and a colour reference; the cut list with quantities; and the destination port. Hinge holes, handle cut-outs and mitre cuts are machined in the same plant as the press; CNC machining of aluminum profiles covers what is better cut before anodizing and what is better left until after. If you have a section already running elsewhere, send it with the panel thickness and the span — we will tell you where it is likely to fail before we quote. If you only have a sketch, send the sketch: die design is done in-house, and a section can usually be adjusted for wall balance and metal flow long before a die is cut.
Q: Which aluminum alloy is best for furniture profiles - 6063 or 6061?
A: 6063 for anything with a visible face, and 6463 where the anodized finish has to be bright and clean. 6061 or 6082 only where the profile carries load: table legs, bench frames, brackets. Alloy barely affects stiffness - 6063 and 6061 are both around 69 GPa - so a sagging shelf is a span and section-depth problem, not an alloy problem.
Q: What wall thickness should a cabinet or wardrobe frame have?
A: Our floor is 0.8 mm, but failures at that thickness are rarely strength failures. They are hinge screws pulling out, dents from handling, or a groove wall that flexes. Let the load path decide: a door frame is governed by its hinge screws, a wardrobe jamb by the panel in the groove, a leg by buckling. Send the span and the load and we will check deflection before quoting a wall.
Q: Can you hold the groove tolerance for an 18 mm panel?
A: Grooves are held to +/-0.1 mm. The larger variable is the panel: an 18 mm board is rarely 18.00 mm and it moves with humidity. Tell us the measured panel thickness and whether the fit should be free or tight after finishing - AA15 anodizing closes the groove by about 0.03 mm, a 70 micron powder coat by about 0.14 mm.
Q: Will a reorder match the colour of the first batch?
A: It will if a sealed master sample and a colour-difference limit were agreed at the start. Dye bath condition, temperature and the alloy batch all shift colour, so "the same black as last time" is not a specification. Ask for the master sample to be kept and for reorders to run on the same anodizing batch where quantity allows.
Q: What is the MOQ, and what does the die cost?
A: 500 kg per profile, whether the die is new or existing. Die tooling is quoted per project, because cost follows section complexity and press size, so it is not published as a price list. Ask for tooling as a separate line with die ownership and storage written into the quotation.
Q: How long can the profiles be, and how are they packed?
A: There is no standard length; profiles are cut to your cut list. A 20' container takes up to 5.85 m, a 40' takes 6.0 m and can carry two lengths. Cuts under 5 m carry a sawing charge. Packing is per order: protection film, interleaving, end caps and bundle labels matched to the packing list.
Q: Should furniture profiles be anodized or powder coated?
A: Anodizing at AA10 or AA15 for visible metal faces and parts that get handled - it does not chip at a mitre. Powder coating when the colour has to match a brand or a RAL that anodizing cannot reach; it builds 60-80 micron, so check what it does to any groove or sliding fit. PVDF is rarely specified on furniture because of cost.
Q: Can you machine hinge holes, handle cut-outs and mitres?
A: Yes. Sawing, drilling, milling and tapping run in the same plant as the press, so hinge holes, handle cut-outs, mitre cuts and end milling can ship as finished parts instead of loose profiles. Send the hole pattern with the section drawing; if the wall is around 1 mm at a screw position we will suggest a web or an insert.

=== Thermal Break Window and Door Profiles ===
URL: https://www.linkedalu.com/products/architectural-aluminum/windows-doors/thermal-break-window-door-profiles.html
Summary: Thermal break aluminum window and door profiles in 6063-T5, built as two extrusions joined by a PA66-GF25 polyamide bridge. Extruded, finished and cut to your section drawing and cutting list in Foshan.
- Alloy: 6063-T5
- Wall thickness: 0.8 mm minimum
- Weight tolerance: ±10% of theoretical weight
- Thermal bridge: PA66-GF25 polyamide strip, width set by the strip
- Finish: Mill / anodized AA10–AA15 / powder coated
- Length: Cut to your cutting list
- Container length: 20 ft to 5.85 m / 40 ft to 6.0 m
- Minimum order: 500 kg per section
- Standards: GB/T 5237 · EN 755 · ASTM B221
- Loading port: FOB Shenzhen / Guangzhou
What a thermal break window profile actually is Thermal break window and door profiles in 6063-T5, walls from 0.8 mm, with a PA66-GF25 polyamide strip crimped into the section and weight held within ±10% of theoretical. Cut to your cutting list — 20 ft containers take 5.85 m, 40 ft take 6.0 m. 500 kg per section. A thermal break window profile is two aluminum extrusions joined only by a polyamide strip, so inner and outer faces are not one piece of metal. A standard hollow window section is a single extrusion. Heat moves from the warm face to the cold face through the metal itself, and aluminum is very good at that. The result is a frame that behaves like a radiator between inside and outside, however thick the glass. In a thermal break section the profile is no longer one piece. The outer part carries the weather face, the glazing rebate and the drainage path. The inner part carries the interior face and the hardware. Between them sits a strip of glass-fibre reinforced polyamide, PA66-GF25, and that strip is the only structural connection between the two halves. Because the metal is interrupted, heat crossing the frame has to pass through the polyamide. Polyamide conducts heat roughly 600 times more slowly than aluminum — around 0.3 W/(m·K) against roughly 200 W/(m·K) for the alloy. The frame stops short-circuiting the glass. What the polyamide bridge has to do — and how wide it is The strip is structural, not a gasket: it carries wind-load shear and holds the two halves in register, and its width is what sets the bridge width. This is the part most drawings get wrong. The bridge is not an insulator pushed into a slot as an afterthought. It is the joint. Every wind load on the frame arrives as shear across that strip, and the strip has to hold the two aluminum halves in alignment for the service life of the window. Plain polyamide would creep under that load and the joint would open. PA66 with 25 percent glass fibre keeps the joint stiff, keeps the two halves in register, and stays dimensionally stable across the temperature range a facade actually sees. Nearly all thermal break window profiles are made by crimping the strip in: the polyamide is locked between the two aluminum extrusions, so the finished section is two aluminum parts joined only by the strip. The older cast-in route, where the polyamide is poured into a channel and the metal web milled away, is rare today. Whichever route was used, the drawing has to end with one continuous non-metallic path across the section. If a metal web survives anywhere along that path, that point conducts. The bridge width is not a free design number. It is the width of the strip you specify, and polyamide strips are extruded in a fixed range of widths rather than made to any size. 14.8 mm is the width in widest use across window and door work, and the width is matched to the depth of the frame series rather than chosen for effect. Wider is not automatically better: beyond a point the gain in frame U-value flattens out, while the section gets heavier, less stiff and more expensive. Tell us the series you are working to and we will quote the strip width with the section. What the strip does not do is rescue poor glazing. A frame with a correct break, a single pane and an aluminum spacer still condenses, because the frame is only one of three paths between inside and outside. Frame, glass and spacer have to be dealt with together. Where the break sits, and why the section shape matters The break must run continuously around the frame: any point where metal crosses it cancels insulation there, whatever the rest of the section does. Position matters as much as presence. The break belongs on the boundary between the weather side and the interior side, so that the condensation plane stays on the warm side of the barrier. Put it too far out and the inner aluminum half becomes a cold surface that collects water on a winter morning. Chamber design works with the break rather than instead of it. A multi-chamber section breaks the cavity into smaller cells so air inside cannot circulate freely and carry heat across the frame. You can see this in our sections: the hollow cells behind the break are there to stop internal convection, not to add stiffness. Drainage has to be arranged so that water leaves the section on the outdoor side and never crosses the barrier. A drain slot cut straight through the break is a metal-and-water shortcut, and it is easy to miss on a drawing. Finally, the T-slots and hook slots running along the rebate are for EPDM gaskets and glazing seals. They are sized so the seal compresses against the glass and the sash without being over-compressed, which is what keeps wind-driven rain out of the cavity. The traps that quietly cancel a thermal break Fixings, corner joints, sills and hardware bridge a break more often than the profile fails, so check the joints before arguing about cost. A correctly broken section can still perform like a solid one, and the reasons are almost always at the joints rather than in the profile: Screws and fixing ports that pass straight through the break. A screw crossing both aluminum halves is a direct metal path. Where the hardware has to fix through, the port should be arranged so the screw lands in one half only. Corner joints without a thermal break. Crimped or cleated corners connect the two halves of the frame. A corner that is mechanically continuous from inside face to outside face undoes the break at the most exposed point of the window. Unbroken sills and thresholds. Door thresholds are the usual casualty, because they are asked to take traffic and the break is sacrificed to stiffness. The glazing spacer. An aluminum spacer between the panes conducts around the edge of the glass and can dominate the whole window, particularly in a small unit where edge area is large relative to the centre. Metal hinge and handle plates. Hardware fixed to both halves of the frame is a bridge, and it is also the part a buyer never thinks to check. None of this argues against thermal break sections. It argues for checking the whole assembly, because the frame's contribution is only worth what the joints allow. Alloy, temper, wall thickness and finish we hold We extrude these sections in 6063-T5 with a minimum 0.8 mm wall, and hold extrusion weight to within ±10 percent of theoretical weight. 6063-T5 is the standard choice for architectural sections: it takes anodizing and coating evenly, extrudes into the thin walls a window section needs, and holds strength after artificial ageing. Where a project needs more strength than 6063 gives in the section available, tell us the requirement at enquiry and we will say plainly whether the drawing is better served by a different alloy. Wall thickness is quoted as the minimum on the drawing, not an average, and the sections we run for windows and doors are held at 0.8 mm and above. Weight tolerance of ±10 percent against theoretical weight is what the mill certificate shows, and it is the figure that tells you whether the die is running where it should. Finishing is where most window and door projects differ. Mill finish suits sections that will be coated or wrapped downstream. Anodizing is our main architectural finish, in AA10 and AA15 film thicknesses for exterior use and thinner films for interior trim, and it is covered in detail on our anodized window and door frame profiles page. Powder coating to a RAL color gives the widest color range and is described on our powder coated window and door profiles page. PVDF coating for high UV exposure is available on request. One point on ordering finishes: the two aluminum halves of a thermal break section are extruded and finished separately, then assembled. That makes the finish schedule part of the section definition, not a separate line item, and it is worth agreeing before the dies are made. Lengths, containers and minimum order No standard length — we cut to your list. A 20 ft container takes up to 5.85 m, a 40 ft up to 6.0 m. Minimum order is 500 kg per section. There is no standard length for architectural profiles. Windows are cut from a cutting list, the list drives the bar length, and the bar length drives the container. Send the cutting list and we will work back from it. The limits are worth knowing before you plan a project. A 20 ft container takes a maximum length of about 5.85 m. A 40 ft container takes about 6.0 m, which allows two lengths per bay in the standard arrangement. A 45 ft container can go to around 6.4 m, but these are less common on some trade lanes and should not be planned around. Lengths under 5 m carry a sawing charge, because cutting short bars out of standard stock costs the same in handling as a long one. If your cutting list is dominated by short lengths, it is usually cheaper to take a longer bar and cut it yourself. Minimum order is 500 kg per section, and that applies to new dies as well as to sections we already run. We do not publish die charges as a list; the cost depends on the section, so it is quoted with the section. Standards we produce to We produce to GB/T 5237, EN 755 and ASTM B221, and supply the inspection documents your project names — tell us which at enquiry. GB/T 5237 is the Chinese standard for wrought aluminum alloy extruded profiles for architecture and is the base specification our domestic and much of our export work runs to. EN 755 covers extruded aluminum bar, tube and profile for the European market, and ASTM B221 covers extruded aluminum alloy bars, rods, shapes and tubes for North American projects. These three differ in how they express tolerances, in temper designations and in the inspection documents supplied, so naming the standard at enquiry is what makes a quotation comparable between suppliers. If your project calls for a certification scheme we do not hold, we will say so at enquiry rather than at shipment. Alongside the standard, every shipment carries the mill certificate for the heat concerned. Where a project needs an inspection document we do not normally issue, the time to raise it is with the enquiry, because it changes what has to happen at the press rather than at despatch. What to send for a quotation you can compare Send the section drawing, alloy and temper, finish, cutting list and quantity, and we will quote FOB Shenzhen or Guangzhou against those five items. Quotations for window and door profiles diverge mostly because the enquiries did. Five items fix that: The section drawing, ideally as a dimensioned cross-section with wall thicknesses marked. If the drawing shows a thermal break, mark the break line and the strip width. Alloy and temper as the project specifies them, or the performance you need and we will say what section and alloy will deliver it. Finish — mill, anodized with the film thickness you want, or powder coated with the color reference. Cutting list, with quantities per length. Total quantity per section, so we can confirm it clears the 500 kg minimum. Send those and you get a quotation with the section, length, finish, quantity and Incoterm stated, rather than a price per kilogram that leaves you guessing what it covers. If a section is new to us, we will tell you what happens at the die stage and how long it takes before you commit. Thermal break window and door profiles are one part of what we extrude. The same plant runs architectural aluminum profiles across windows, doors, facades, handrails and industrial sections, in 26 extrusion presses and around 100,000 tonnes a year, all in-house. If you want to discuss a section or send a drawing, contact us and we will answer with specifics rather than a brochure.
Q: What is a thermal break in an aluminum window profile?
A: The profile is extruded as two separate aluminum parts joined only by a glass-fibre reinforced polyamide strip (PA66-GF25). Heat crossing the frame has to pass through the polyamide, which conducts roughly 600 times more slowly than aluminum, so the frame no longer short-circuits the glazing.
Q: Is the polyamide bridge strong enough to carry wind load?
A: Yes. The bridge is a structural part, not a gasket: it carries the shear between the two aluminum halves and the bending that comes with wind load. The 25 percent glass fibre in PA66-GF25 is what keeps that joint stiff and stops it creeping over the life of the window.
Q: What is your minimum order for thermal break profiles?
A: 500 kg per section. The same minimum applies to new dies as to sections we already run, and we do not publish die charges as a list because the cost depends on the section.
Q: What lengths can you supply?
A: There is no standard length. Profiles are cut to your cutting list: a 20 ft container takes up to 5.85 m and a 40 ft container up to 6.0 m. Lengths under 5 m carry a sawing charge, so it is often cheaper to take a longer bar and cut it yourself.
Q: Which finishes are available on thermal break sections?
A: Mill finish, anodizing in AA10 and AA15 film thicknesses, and powder coating to a RAL color. The two aluminum halves are finished separately and then assembled, so the finish schedule has to be agreed before the dies are made. PVDF coating is available on request.
Q: Which standards do you produce thermal break profiles to?
A: GB/T 5237, EN 755 and ASTM B221. Tell us at enquiry which inspection documents your project needs; where a certification scheme is not one we hold, we will say so at enquiry rather than at shipment.
Q: What thermal barrier do you use?
A: PA66-GF25 polyamide strip. The strip is the thermal break; the aluminium either side of it carries the structure.
Q: What bridge width is standard?
A: 14.8 mm is the width in most general use. The strip comes in fixed widths, so the bridge width is set by which strip the system needs.
Q: What is the minimum order?
A: 500 kg per section, whether or not a new die is required.

=== Screen Enclosure and Screen Room Aluminum Frame Profiles ===
URL: https://www.linkedalu.com/products/architectural-aluminum/sunrooms/screen-enclosure-screen-room-aluminum-frame-profiles.html
Summary: Custom screen enclosure, screen room and flyscreen frame profiles extruded to your drawing — spline channels held to ±0.1 mm at the GB/T 5237 high-precision grade, with posts, beams, roof members and bottom rails in 6063-T5 or T6.
- Alloy & Temper: 6063-T5 for bottom rails, screen stops and door surrounds / 6063-T6 for roof members and posts over 2.5 m
- Profile Range: Posts, top and bottom beams, roof members, kick plates, door frames, screen stop and channel sections
- Wall Thickness: from 0.8 mm; 1.0-1.5 mm typical for screen members
- Screen Channel: Channel mouth held to ±0.1 mm, at the GB/T 5237 high-precision grade, sized to your spline diameter and mesh
- Tolerance: GB/T 5237 high precision (tighter than equivalent EN / ASTM tolerance classes)
- Weight Tolerance: ±10% on total order weight
- Surface Finish: Powder coating (standard), anodizing AA10 / AA15, PVDF on request
- Standard Length: None - cut to your cutting list; 20 ft container max 5.85 m; 40 ft / 40 HQ 6.0 m with two lengths per container
- MOQ: 500 kg per profile
- Lead Time & Terms: 15-25 days after die approval; FOB Shenzhen / Guangzhou
A screen enclosure is not a sunroom with the glass taken out. It is an unconditioned structure whose whole job is to hold a mesh skin flat and in tension against wind, and to still be holding it after ten years of sun. That one difference moves the critical dimension on the drawing somewhere most buyers never look. We are a custom aluminum extrusion manufacturer in China and an OEM supplier of screen enclosure, screen room, flyscreen and mosquito screen frame profiles: posts, top and bottom beams, roof members, kick plates, door frames, and the screen channel sections that hold the mesh. Everything is extruded, finished and machined to your drawing at one plant in Foshan, Guangdong — 26 extrusion presses, 100,000 tonnes a year, shipping to more than 50 countries since 2005. What a Screen Enclosure Frame Has to Do A screen frame is decided by three things, not by its thermal break: the screen channel, the member section, and the bottom rail drain path. A sunroom specification is dominated by the thermal break, because a sunroom is conditioned. A screen enclosure is not. There is no glass to keep warm and no dew point to stay above, so a polyamide barrier is not the variable that decides whether the part works. It is available on request where part of an enclosure is glazed, and for the great majority of screen frames it is money spent in the wrong place. The sections we run for partly glazed work are cut on the same dies as our sunroom and veranda frame profiles, so a frame can carry glass and mesh on the same post line. Three things decide a screen frame instead: The screen channel, because it decides whether the mesh stays in. The member section, because wind load on screening is higher than most people assume, and deflection is what the end customer actually sees. The bottom rail and the water path, because standing water destroys a frame from the inside, where nobody looks until the coating has already gone. Everything else — finish colour, cap detail, corner joint — is visible, but rarely fatal. The Screen Channel: Where These Frames Actually Fail The channel mouth is the failure point. It is held to ±0.1 mm, at the GB/T 5237 high-precision grade, because the dimension grows as the die wears. When a screened panel pops out after two summers, the mesh is not the problem and the spline is not the problem. The fit between the two is. A screen channel has one job: compress the mesh against the base of the groove hard enough that friction and the undercut hold it, and gently enough that the mouth does not open up. Four dimensions do that work, and all four are cut into the die: Mouth width. Sized from the spline diameter, not picked from a table. A mouth that is wide relative to the spline lets the spline walk out under load; a mouth that is too tight will not let the installer seat the spline without distorting the channel, and a distorted channel never grips properly again. Groove depth. The spline has to push the mesh all the way to the groove base. In a shallow groove the mesh is trapped only at the lip, and the lip is the first thing that releases in a hard wind. Undercut or return lip. This is the mechanical lock. Channels without a return depend on friction alone, and friction is the first thing heat takes away. Base radius. A square groove base cuts the mesh under tension. The radius at the base is why a properly cut profile does not tear at the groove and a cheap one does. We hold the channel mouth to ±0.1 mm. That is the GB/T 5237 high-precision grade — tighter, in our experience, than the equivalent EN and ASTM tolerance classes on the same dimensions — and it is the grade we run as standard rather than something upgraded per order. The mouth is measured through the run rather than once on the first billet, because it grows as the die wears. A channel that grips perfectly at billet five hundred can be loose by billet fifty thousand — and the customer discovers it as panels popping out a year after installation, long after the profile was accepted. Send us the spline diameter, the mesh type — insect weave, a fine flyscreen mesh, or a heavier coated mesh — and the installation method, and the channel is cut to ±0.1 mm on that combination. We do not publish a generic channel, because a groove sized for one spline and one mesh crimp will not hold a different pair. The five field failures that follow from getting this wrong, and the other four, are set out in our note on sunroom and screen room problems and how to engineer them out. Spans, Alloy and Deflection Screen frames are governed by wind, not weight: 6063-T5 under 2.5 m, 6063-T6 past it, 6061-T6 for long spans. Check deflection, not stress. Screen enclosure members are light, and that is exactly why they deflect. A screen panel presents far more sail area than its weight suggests, so roof members and tall wall posts are usually governed by wind rather than by dead load, and glazing is not there to stiffen anything. The alloy follows the span, the same way it does on any frame we extrude: Short spans and non-structural members — bottom rails, kick plate returns, screen stops, door surrounds. 6063-T5, usually 1.0–1.5 mm wall. Roof members and wall posts over roughly 2.5 m. 6063-T6, which gives about 30% more yield strength in the same section than T5. Long spans, high design wind speeds, or a member carrying both roof and screen load. 6061-T6 nearly doubles the yield strength of 6063-T5. 6005A-T6 is available on request where a project specifies it. Two levers usually decide the outcome, and the cheaper one is almost always geometry. Deepening the section raises stiffness far faster than moving up an alloy family, and it does not change the finish, the fasteners, or the connection detail. The alloy change is what you reach for when the depth is already fixed by a cap, a head detail, or the space between two posts. Check deflection to a stated limit — L/180 is a common limit for roof members — rather than checking stress alone. A screen frame almost never fails structurally. It goes out of sight line first: a roof member that sags between posts, a door that stops closing square, a panel that reads as bowed from the far side of the terrace. Those are deflection failures, and they are visible long before anything yields. Tell us the span, the post spacing, the design wind speed your project is permitted under, and the deflection limit your engineer is working to. The die is sized around that set rather than chosen from a catalogue. Wind, Water and the Bottom Rail A bottom rail with no weep path holds water along its full length. Drain it at the low end of the run, and keep fasteners out of the water path. Water always reaches a screen frame. The design question is where it goes next, and on a screen enclosure the answer is decided at the bottom rail, the kick plate and the post base. Drain the rail, do not seal it. A bottom rail with no weep path holds a bead of water along its whole length after every storm. That is where coating fails first, where the frame stains, and where the fastener at the lowest point corrodes. Put the weep holes where the water actually collects, which is the low end of the run, not evenly spaced. On a long level rail, evenly spaced holes let the middle of the rail hold water. Keep the fastening points out of the water path. A screw that sits in standing water is the first thing to fail, and it takes the coating around it with it. Detail the kick plate so water running down the mesh discharges outside the frame line, not into the joint between the rail and the deck. On sloped screen roofs, never rely on sealant as the primary barrier. Sealant is a secondary defence behind geometry. Finish and Fasteners for Coastal and High-UV Sites Powder coating is standard; anodizing runs AA10 or AA15. Isolate stainless fasteners — galvanic staining is the most common appearance failure. Screen frames sit outdoors in full sun and are almost never cleaned. In the coastal, desert and high-UV markets these frames are usually specified for — the Gulf, North and West Africa, Latin America and Southeast Asia — the finish is competing with UV, heat, salt and dust at the same time. Powder coating is the finish we run most for these frames. It holds colour across a batch, which matters when a frame is fabricated from several sections and assembled on site. Anodizing is available in AA10 or AA15 where a metallic finish or abrasion resistance is wanted. PVDF systems are quoted on request where a project's specification calls for them, and hard-coat anodizing is rarely specified on screen frames — it is quoted on request rather than offered as a standard route. Three points decide how long a screen frame stays acceptable on a coastal or desert site: Isolate the fasteners. Stainless steel fasteners into aluminum in coastal air produce staining at every fixing point unless the joint is isolated. Nylon washers, isolating sleeves or a coated fastener take the couple out of the assembly. This is the single most common appearance failure we see on frames that were otherwise built correctly. Cover the cut ends and drilled holes. Extrusion is coated in line, so a profile is protected on its face and bare at every cut and every punch. Site-cut members and drilled fastener holes need a touch-up procedure or they will bloom first. Choose the colour for the coating's sake as much as the design's. A dark frame in high-UV service runs hotter and works the coating harder. Where a project has a free choice of colour and a long service life, a lighter tone is the lower-risk decision. Every shipment leaves with the composition, mechanical properties, dimensional and coating reports. Mill test report supplied with every shipment. Fabrication, Length and Container Loading There is no standard length. A 20 ft container takes 5.85 m; a 40 ft takes 6.0 m with two lengths inside. Under 5 m adds a cutting charge. There is no standard length on these profiles. Sections are cut to the length your program needs, from your cutting list. What does matter is how the length loads: A 20 ft container takes a maximum of 5.85 m. A 40 ft standard container and a 40 ft high cube take 6.0 m, and two lengths fit along the container. This is the standard export route for 6 m material, and it is why 6.0 m is the practical module for full-length posts and roof members: two sections load end to end inside a 12 m cargo space. A 45 ft container will take up to 6.4 m, but we do not plan an order around one. 45 ft equipment is scarce on most trade lanes and a number of terminals will not handle the box, so a schedule that depends on it is a schedule carrying a risk. Lengths under 5 m carry an additional cutting charge. Short members mean more saw setups and more offcut per bundle, and on a frame set with many short elements — door surrounds, kick plate returns, screen stops — that cost is real. Members that will not fit the container are cut down and joined on site with connector stock, or split into two lengths with a splice detail on the drawing. Cutting, punching, tapping, milling and notching are all carried out before shipment. Corner notches and mitre cuts are made on our machines so the joint closes properly on site rather than being filed to fit by the installer. Hardware holes can be pre-drilled to your bracket pattern. Profiles are bundled in shrink film for transit. Ordering: MOQ, Tooling, Lead Time and Terms MOQ is 500 kg per profile, tooling is quoted per project, and lead time is 15–25 days after die approval. Weight tolerance is ±10%. Minimum order quantity is 500 kg per profile. On a frame set with many sections, that lets a small system travel in the same container as a full one instead of forcing a separate order per section. Die tooling is quoted for the project. It depends on the section size, the number of hollow chambers and the screen channel detail, so it is priced against your drawing rather than from a public list. Extruded weight tolerance is ±10%. A 500 kg nominal order can arrive between about 450 kg and 550 kg, and it is worth building that into your costing before the PO rather than after. Typical lead time is 15–25 days after die approval, including finishing and machining. Terms are FOB Shenzhen or Guangzhou. Export packing is to your requirement, including mill-length bundles or cut-to-size crates. Profiles are supplied to GB/T 5237 high-precision tolerances. Critical dimensions are controlled at the die rather than corrected after extrusion. Export documentation travels with the goods. Composition, mechanical properties, dimensional and coating reports ship with every order. As an OEM aluminum extrusion supplier and a custom aluminum extrusion manufacturer in China, we work from your drawing and your branding, on your packaging and your documentation requirements. If you are placing a first order and want to judge whether a factory is reliable before you commit a programme to it, ask for a section sample off the production die before the balance of the run is finished — we would rather catch a channel dimension at sample stage than hear about it as a claim. Typical Applications and What to Send for a Quotation Send drawings, alloy and temper per section, span and post spacing, design wind speed and cutting list. We check manufacturability before quoting. Patio and terrace screen enclosures, and pool surrounds Screen rooms, porch enclosures and covered outdoor areas Flyscreen and mosquito screen frames for windows, doors and ventilation openings Roof members, posts and beams for screened roofs and pergolas Kick plates, bottom rails and screen stops Door frames, screen door sections and hardware surrounds Partly glazed enclosures where a thermal break section is specified To start a quotation, send cross-section drawings for the full set, the alloy and temper required per section, span and post spacing, design wind speed, the spline diameter and mesh type, finish type and colour reference, quantity per section, and your cutting list. We review manufacturability, flag any section that will not extrude cleanly or hold the channel dimension you need, and quote from there.
Q: Can you extrude a complete screen enclosure frame set rather than individual bars?
A: Yes. A frame set is our normal way of working: posts, top and bottom beams, roof members, kick plates, door frames, screen stops and the channel sections are extruded, finished and machined together from your drawing set. Because the sections are produced in one batch they fit each other and match in finish, instead of arriving from several suppliers with slightly different channel dimensions and shades.
Q: How do you size the screen channel, and what spline information do you need?
A: The mouth width, groove depth, undercut and base radius are cut into the die from your spline diameter and mesh type rather than taken from a standard table. The channel mouth is held to ±0.1 mm at the GB/T 5237 high-precision grade and checked through the production run. Send the spline diameter, the mesh type (insect weave, a fine flyscreen mesh or a heavier coated mesh), the mesh crimp, and the installation method.
Q: What lengths can you supply, and which container do they ship in?
A: There is no standard length - sections are cut to your cutting list. A 20 ft container takes a maximum of 5.85 m. A 40 ft standard container or a 40 ft high cube takes 6.0 m, with two lengths fitting along the 12 m cargo space. A 45 ft container will take up to 6.4 m, but we do not plan an order around one: 45 ft equipment is scarce on most trade lanes and some terminals will not handle the box. Lengths under 5 m carry an additional cutting charge.
Q: Do you supply thermal break sections for screen frames?
A: Only where part of the enclosure is glazed or the space is conditioned. A screen enclosure is an unconditioned structure, so a polyamide barrier is not the variable that decides whether the profile works, and it is available on request rather than offered as a standard route.
Q: What is the minimum order, how is tooling priced, and what are the terms?
A: Minimum order is 500 kg per profile, which lets a small frame set travel in the same container as a full one. Die tooling is quoted for the project - it depends on the section size, the number of hollow chambers and the screen channel detail, so it is priced against your drawing rather than from a published list. Extruded weight tolerance is ±10%, lead time is 15-25 days after die approval, and terms are FOB Shenzhen or Guangzhou.
Q: What finish do you recommend for a coastal or high-UV site?
A: Powder coating is what we run most for these frames, in a colour light enough not to work the coating harder than it needs to. Anodizing in AA10 or AA15 is available where a metallic finish or abrasion resistance is wanted. Whatever the finish, isolate stainless fasteners from the aluminum at every fixing point and touch up cut ends and drilled holes - those are the two appearance failures we see most on otherwise correct frames.
Q: Do you supply the rails and posts as one set?
A: Yes. The rail, post and corner sections are normally run as one die family so the fit between them is controlled at the die rather than at assembly.
Q: Which alloy for screen frames?
A: 6063-T5 for nearly all screen and enclosure work. It extrudes cleanly at the thin walls these sections need.
Q: What is the minimum order?
A: 500 kg per section, whether or not a new die is required.

=== Aluminum Heat Sinks for AI Servers, GPUs and HPC Cooling ===
URL: https://www.linkedalu.com/products/industrial-aluminum/aluminum-heatsinks/aluminum-heat-sinks-ai-server-gpu-hpc-cooling.html
Summary: Custom extruded aluminum heat sinks, skived-fin sinks and friction-stir-welded cold plates for AI server, GPU and HPC cooling — engineered from your thermal map and machined in-house in Foshan.
- Alloy: 6063-T5 standard; 6061-T6 and 6005A-T6 on request
- Temper: T5, T6
- Fin height: to 50 mm standard; 80 mm on a dedicated die
- Fin tip thickness: 0.5 mm min as-extruded; 0.2–0.4 mm CNC-skived
- Fin pitch: 2.5 mm standard, 1.5 mm minimum
- Base thickness: 2–20 mm (8–15 mm typical for chip mounting)
- Section width: 10–300 mm standard presses; to 420 mm on the large press
- Chip face flatness: 0.05 mm or better, Ra 1.6 µm or finer, CNC face-milled
- Cold plate: 3–8 mm extruded channels, friction stir welded, 0.5–1.5 MPa working, ≥3.0 MPa burst
- Finish: Mill, black anodized AA10/AA15, sandblasted
Extruded heatsinks for high-power AI server and GPU cooling AI accelerator cooling stopped being a conventional heat-sink problem some generations ago. Power per package has roughly doubled twice since the first server-class accelerators, a single GPU board can now carry two or four packages with an HBM stack beside each die, and the voltage regulator adds its own losses. The part our customers ask us to extrude is no longer a finned block with a fan in front of it. It is either a high-aspect-ratio fin stack, a heat spreader that has to move heat sideways before it can move it out, or a channeled body for coolant. Linkedalu Metal Group Co., Ltd extrudes heat sinks for AI server, GPU and HPC programs on three routes — direct extrusion, CNC skiving, and friction-stir-welded cold plates — and machines the chip interface in-house. Die design, extrusion, finishing and fabrication run in one plant in Foshan, Guangdong: 26 extrusion presses, 100,000 tonnes a year, shipping to 50+ countries since 2005. What high power density changes in the extrusion We do not publish accelerator specifications. Power per package, die area and hotspot maps change with every generation, and they are your design input, not our product — what we work from is the number you send us and the cooling mode you have decided on. Three things are true of every high-power device we extrude for, and they are what make this a different job from a 50 W heat sink. Heat enters through a small footprint. Power is delivered across a die area measured in hundreds of square millimeters, not spread across the base of the heat sink. The base therefore has to spread heat laterally before the fins can remove it, which puts base thickness and spreading resistance ahead of fin count on the list of variables the die engineer sets. Air cooling has a practical per-device ceiling. Around 700 W per package is where air stops being the economical answer in a rack-mounted chassis — the fin surface area and the volumetric flow needed to carry the heat away begin to exceed what the chassis fans and the room can supply. Above that point the coolant comes to the chip, and the extruded part changes from a fin stack to a channeled cold-plate body. The chassis sets the envelope and the loop sets the pressure budget. High-density compute is a liquid-loop mechanical design problem now. A cold plate is a component in that loop with a pressure-drop allowance, and the extruded section is where that allowance is either spent or saved. So the drawing should arrive with four numbers: power per package, package footprint, cooling mode with its available airflow or flow-and-pressure budget, and the mechanical envelope. Everything downstream of those is die design. Where an extruded aluminum heat sink still wins Copper conducts better — around 385–400 W/m·K against 209 W/m·K for 6063-T5 — and it is still the wrong default for most of this work, for three reasons. Mass. Aluminum is 2.70 g/cm³ against copper's 8.96. On a card that is already at its mechanical and connector loading limits, a copper sink is often the part that does not fit the specification at all. One-piece construction. Fins, base, mounting channels and fastener bosses come out of the die as a single section. There is no joint and no interface resistance between fin and base, and no bond line to qualify. Features in the extrusion. Card guides, screw channels, board stand-offs and cable routing can be extruded into the section. On a GPU card, the mounting geometry is as much of a problem as the thermal one. The ceiling on extruded fin density is set by the die, not by the drawing you send. As a guide: fin tip thickness 0.5 mm or more as-extruded, fin height to 50 mm as standard and to 80 mm on a dedicated die, fin pitch 2.5 mm as standard with 1.5 mm as the practical minimum, base thickness 2–20 mm, section width 10–300 mm on standard presses and to 420 mm on the large press. Where a design needs more surface area than those limits allow, CNC skiving produces fins of 0.2–0.4 mm, and bonded or inserted fins cover the very large sections. Send the thermal map, not just the drawing The most common cause of a lost month on an AI thermal program is a quote request that contains a drawing but no thermal specification. A drawing tells us the shape. It does not tell us why the shape is that shape, and on a high-power part the shape is downstream of the physics. What we need to quote properly: power per package, in watts, and the number of packages on the card or board the die footprint and, where available, the hotspot map across it — not just the average the thermal interface material you have selected, and its rated conductivity at bond-line thickness cooling mode: air, with the airflow or face velocity available; or liquid, with coolant type, flow rate, inlet temperature and the pressure-drop budget ambient, maximum junction temperature, and the rack or chassis envelope the part has to fit alloy constraints, surface treatment, and annual quantity With those numbers the die engineer proposes two or three section concepts — extruded fin stack, skived fins, or a channeled cold plate — and states what each one costs in tooling and lead time. If a feature will not fill properly, or the die tongue between two fins will not survive the run, we say so before anyone cuts steel. What actually binds fin design at the die Fin count on a drawing is a wish; the die decides what is real, and the binding feature is not the fin — it is the tongue of die steel between two fins. That tongue has to withstand the extrusion pressure without deflecting or cracking, and the taller the fins, the more unsupported tongue there is to fail. That is why pitch cannot be quoted independently of fin height. A fin stack under 10 mm tall holds a tight 1.5–2 mm pitch comfortably. Push fin height to 50 mm and the geometry needs roughly 3–5 mm spacing, because there is now 50 mm of die steel standing between each pair of fins. The widely repeated "extrusion can hold 15:1" rule of thumb describes a specific combination of tip thickness and height; it is not a general licence to draw 0.5 mm fins 60 mm tall, which is 120:1 and will not run. Three practical notes from production: Tip thickness before pitch. A 0.5 mm tip on a 50 mm fin survives; 0.3 mm does not, because the tip has to fill before the metal behind it solidifies. Taper helps. A fin that tapers from a thicker root to a 0.5 mm tip is easier to run than one with parallel sides, at a thermal penalty you can calculate. Corner radii. Sharp internal corners concentrate stress in the die. A small radius added to a fin root frequently turns a design we would refuse into one we run every day. The chip interface: flatness, roughness and mounting The base is a thermal interface before it is a structural part, and as-extruded flatness is not good enough for a semiconductor. Extrusion leaves roughly 0.2 mm of deviation per 100 mm; a graphics die needs an order of magnitude better than that, so the contact face is CNC face-milled after extrusion. Our standard on these parts is 0.05 mm flatness or better at the chip face, with surface roughness of Ra 1.6 µm or finer so thermal paste spreads evenly instead of pooling. Interface resistance is proportional to bond-line thickness and inversely proportional to the conductivity of the interface material. As a working figure, with a typical thermal paste or gap pad, every additional 10 µm of bond line costs roughly 0.01–0.03 K·cm²/W. That looks small until it is multiplied by the flux entering the base: on a package dissipating several hundred watts through a footprint of a few hundred square millimeters, the difference between a milled contact face and an as-extruded one is no longer a rounding error. That is the whole reason the tolerance is on the drawing. Mounting features are extruded into the section where the geometry allows: screw channels, card guides, stand-offs. Where a customer concentrates heat at a specific location rather than spreading it across the base, we can extrude a semicircular groove for a heat pipe in the common 6 mm, 8 mm and 10 mm diameters. Surface treatment following the interface is functional, not decorative. The chip contact face is normally left bare — any coating adds a layer in the thermal path. Fins are black anodized in AA10 or AA15 where radiation or corrosion resistance is wanted. Hard-coat anodizing is rarely specified on these parts and is quoted on request rather than offered as a standard option. Liquid cooling: extruded channels, cold plates and friction stir welding Where air is no longer the answer, the part is a cold plate. We extrude the body as a channeled section with 3–8 mm internal channels, close the ends, and join the cover by friction stir welding — a solid-state process that stirs the aluminum into a bond without melting it, so there is no filler metal, no flux and no porosity in the weld zone to open up under thermal cycling. Cold plates are rated 0.5–1.5 MPa working pressure with a burst rating of at least 3.0 MPa, and every unit is pressure-tested at 250 kPa for 60 seconds, with leakage required to stay below 30 Pa. Two design decisions dominate performance on a GPU cold plate: Serpentine versus parallel channels. A single serpentine path is predictable and gives even flow, at higher pressure drop. Parallel paths lower the pressure drop but are vulnerable to maldistribution, so one part of the die gets starved while another is over-cooled. On a part with a hotspot map as uneven as a graphics die, maldistribution shows up directly in junction temperature. Channel cross-section versus pump power. Higher flow velocity improves the heat-transfer coefficient and costs pressure drop roughly with the square of velocity. The practical design point comes from your loop budget, which is why the pressure-drop figure is on our document request list and not an optional extra. Tell us the coolant, the flow rate, the inlet temperature, the pressure-drop budget and the port geometry, and we will propose a channel layout before the die is cut. Export, inspection and documents for AI server programs Every order ships with a mill test certificate to GB/T 5237, EN 755-9 or ASTM B221 carrying chemical composition, mechanical properties and dimensional records, plus a dimensional inspection report for machined features. Extrusion weight tolerance is ±10%, which matters on a program priced by weight. Minimum order is 500 kg per profile; die tooling is quoted for the project. For customs, extruded profiles are normally classified under HS 7604 and machined aluminum articles commonly under 7616.99 — but classification is your customs broker's determination, not ours, and we will supply the composition and processing route data they need to make it. For EU-bound shipments, note that the CBAM definitive regime applies from 1 January 2026. Importers above 50 tonnes a year must hold authorized CBAM declarant status and report embedded emissions per consignment. Send us the data fields your declarant requires and we will confirm, before you place the order, which of them the mill can provide against actual production records. Packing is built for long, thin sections: interleaved profiles, board and foam edge protection, strapped bundles. A 20 ft container takes lengths up to 5.85 m, so 6 m sections ship in a 40 ft container or are cut to length below 5.85 m — a practical decision to settle at quotation, because it changes both freight and the number of joints in the finished assembly. Terms are FOB Shenzhen or Guangzhou, CIF on request.
Q: Can an extruded aluminum heat sink handle a kilowatt-class package on air?
A: It can be made to work, but it stops being the economical answer. Around 700 W per package is the practical ceiling for rack-mounted air cooling; above that, the fin surface area and the air volume needed to remove the heat start to exceed what the chassis and the room can supply. At kilowatt-per-package density, direct-to-chip liquid is the standard route and the extruded part becomes a channeled cold-plate body with a friction-stir-welded cover. If you intend to stay on air, send the actual chassis airflow rather than a nominal fan rating — the answer changes with it.
Q: What changes in the part when power per package doubles?
A: Three things, in order. The base becomes the first design variable, because heat enters through a small footprint and spreading resistance matters more than fin count. Fin tip thickness and pitch move to the extrudable limit, because the surface area requirement has roughly doubled inside the same plan area. And the cooling mode usually changes, which turns the section from a fin stack into a multi-channel cold plate. Send the new power figure with the cooling mode and we will tell you which of the three you are dealing with.
Q: Do we need skived fins, or is an extrusion enough?
A: It comes down to surface area per unit of plan area. An extrusion gives you fin tips of 0.5 mm or more, height to 50 mm as standard and 80 mm on a dedicated die, at the lowest part cost and with no bond line. Skiving takes the fins to 0.2–0.4 mm and roughly doubles the fin count in the same footprint, which is what high-density server sinks use, at the cost of a secondary operation. Send the target surface area and the airflow you have, and we will tell you which route reaches it.
Q: What flatness and surface roughness do you hold on the chip contact face?
A: 0.05 mm flatness or better after CNC face milling, with Ra 1.6 µm or finer, so thermal paste spreads evenly instead of pooling. As-extruded flatness of roughly 0.2 mm per 100 mm is not acceptable at a semiconductor interface, which is why the face is machined on these parts. Anything tighter than 0.05 mm is quoted against the drawing rather than offered as a stock tolerance, because it depends on the machined feature and on how the part is held during milling.
Q: Extruded aluminum or a copper base for a GPU cold plate?
A: Full copper is rarely the answer on a graphics card: at 8.96 g/cm³ it loads the connector and the chassis, and at current metal prices it multiplies the material line. Where the hotspot map is concentrated, the usual construction is a copper base with an aluminum fin stack or cover — copper spreads heat from the die, aluminum adds surface area at a third of the weight. Send the hotspot map and we will say whether the die footprint is concentrated enough to justify the copper interface.
Q: MOQ, tooling and lead time for a new heat sink profile?
A: Minimum order is 500 kg per profile. Die tooling is quoted for the project, so the tooling figure depends on section complexity, the number of cavities and whether the die is a solid or hollow design — we quote it rather than publish a table. Send the drawing and the thermal specification together, and the quotation returns with the tooling, the unit price and the first-sample date, because all three depend on the same die decision.
Q: Can an extruded heatsink cope with AI server power density?
A: Only where the geometry allows it. We size the base and fin field from your thermal map, and say plainly when a skived or bonded assembly is the better route instead of forcing the job through a die.
Q: Do you make friction stir welded cold plates?
A: Yes, in-house. FSW lets us build a cold plate wider than the press can extrude as one piece, without the thermal penalty of a brazed joint.
Q: Do you quote from a thermal map or only a drawing?
A: Both. A drawing gets you a price. A thermal map gets you a design that meets the junction temperature target.

=== CNC Machined Aluminum Solar Inverter Housings & Optimizer Brackets ===
URL: https://www.linkedalu.com/products/cnc-machining-parts/high-precision-aluminum-parts/cnc-machined-solar-inverter-housings-optimizer-brackets.html
Summary: Extruded aluminum solar inverter housings and optimizer brackets, machined in a single fixture — ±0.05 mm hole position, 0.05 mm milled flatness, IP65 verified by a 100 % leak test, FOB Shenzhen / Guangzhou.
- Product Type: CNC-machined aluminum inverter housings, optimizer brackets and sealed enclosure bodies
- Alloy & Temper: 6063-T6, 6061-T6, 6005A-T6; 6063-T5 or 6061-T6 plate for covers
- Machining Processes: Precision sawing, CNC drilling, milling, tapping M3–M16, bore machining, single-fixture multi-axis setups
- Tolerances: Sawing ±0.1 mm; hole position ±0.05 mm; milled flatness 0.05 mm; tapping 6H class; sealing faces Ra 0.8 µm
- Sealing: IP65 verified by 100 % pressure leak test (30 kPa / 60 s, reject above 50 Pa); IP67 on request
- Surface Finish: Anodizing 10–25 µm standard; powder coating 60–120 µm on request; hard-coat anodizing rarely specified — sequenced with machining
- Profile Length: 6 m standard lines; 12 m on long-bed equipment
- Hardware & Assembly: Thread inserts, captive screws, EPDM or silicone gaskets, gland plates; kitted to your BOM
- Lead Time: Prototype 3–7 working days; production 15–25 days after die approval
- MOQ & Trade Terms: Prototyping from 1 piece; series production from 500 pcs; export packing; FOB Shenzhen / Guangzhou (CIF on request)
A solar inverter housing or optimizer bracket has to do three jobs at once: spread heat from the power electronics, keep IP-rated weather sealing for 20+ years of UV and salt-fog exposure, and machine to a tolerance that lets the cover drop on without rework. That is why Tier-1 inverter makers build the housing from an extruded aluminum section and finish it with multi-axis CNC machining in a single fixture, rather than weld sheet-metal boxes. This page shows how we do it at LINKEDALU METAL: alloy and temper selection for outdoor service, CNC tolerances we hold every day (sawing ±0.1 mm, hole position ±0.05 mm, milled flatness 0.05 mm), surface finish selection for outdoor service, and the workflow from drawing to container. Why Extruded Aluminum for Solar Inverter Housings? Custom aluminium extrusion and CNC machining for power inverters: finned housings, mounting rails, covers and brackets in 6063-T6 or 6061-T6, machined to your interface and finished in-house. 500 kg per profile; circumscribed circle to 540 mm. An extruded aluminum section gives the housing a built-in heat-spreading geometry. The die can put fins on the back of the housing, mounting bosses on the sides and a flat sealing face on the front in one continuous profile, without welds or fasteners. CNC machining then opens the cable entries, drills the mounting pattern and mills the cover-sealing face to a tolerance that sheet metal struggles to match. The numbers matter. A sheet-metal inverter box typically uses 1.2 mm galvanized steel at 6.5 kg/m², has 18–24 fasteners around the cover, and needs a silicone bead plus a foam gasket to reach IP65. An equivalent extruded aluminum housing at 2.5 mm wall weighs 2.1 kg/m², uses 8 captive screws, and reaches IP65 with a single EPDM gasket on a milled face. The aluminum version dissipates 35–40 % more heat through the fin root because the section is one thermal path, not a steel box bolted to a separate aluminum heat sink. The catch is that extrusion requires commitment: a new profile needs a die, and die tooling is quoted for the project and amortized over the part volume. For runs above 5,000 housings per year the math almost always favors extrusion. Below that, we will tell you to consider sheet metal or a deep-drawn alternative — we run both, but we will not sell you a die you cannot pay back. What Alloys and Tempers Do You Use for Inverter Housings and Optimizer Brackets? Part Alloy / Temper Why Housing body (visible, finned) 6063-T6 Best anodizing color stability; extrudable to thin 1.5 mm walls; thermal conductivity ~200 W/m·K Mounting bracket, optimizer bracket 6061-T6 Yield 276 MPa for thread inserts and load-bearing rails; better machinability than 6063 Welded sub-frame or pole-mount structure 6005A-T6 Weldable without losing strength in the HAZ; structural-grade (available on request) Heat-spreading baseplate under power electronics 6063-T6 or 6061-T6, anodized One thermal path from the power electronics to the fin root; hard-coat anodizing on request Cover (separate part, machined flat) 6063-T5 or 6061-T6 plate Plate stock CNC machined, then matched to housing face For coastal or salt-air sites, every alloy above also accepts a chromate conversion underlayer before coating. This adds 0.5–1.5 µm of conversion coating and improves coating adhesion and corrosion performance without changing part dimensions. What CNC Tolerances Do You Hold on Inverter Housings? Operation Standard tolerance Typical use Precision sawing (straight or miter) ±0.1 mm Length stops, miter joints at corners CNC drilling ±0.05 mm hole position Mounting patterns, cable glands, fasteners CNC milling — flatness on sealing face 0.05 mm over the machined face Cover-to-housing seal surface Thread tapping M3 to M16, internal, 6H class Cover screws, mounting to rail or wall Surface roughness on sealing faces Ra 0.8 µm (fine) to Ra 1.6 µm (standard) Gasket contact surfaces Maximum profile length 6 m standard; 12 m on long-bed equipment Long rail-format inverter housings Bore tolerances (cable glands, sensor mounts) H7 (+0.015 / 0 mm on 30 mm bore) Press-fit components All drilling and milling of cover-sealing faces, mounting holes and cable entries is done in a single fixture setup on a 3- or 4-axis CNC center. That keeps the relationship between the gasket groove and the bolt holes governed by the machine's positioning accuracy, not by how accurately an operator re-clamps the part between operations. What Surface Finish Survives 20+ Years Outdoors? Two finishes cover most outdoor inverter applications. We pick based on visual priority and atmosphere severity, not cost. Anodizing (Type II, 10–25 µm) The default for visible housings. Clear anodizing on 6063-T6 holds its color for 15+ years in temperate climates; champagne and black anodizing are color-stable for 20+ years. The anodic layer is part of the aluminum itself, so it cannot peel, and it does not chip at the edges the way an applied coating can. Powder Coating (60–120 µm polyester or PVDF) Specified where the atmosphere is harder on the finish than anodizing will tolerate — coastal, industrial or desert sites — or where a specific RAL colour is required. Applied over a chromate conversion underlayer for adhesion. PVDF carries the longer colour-and-gloss warranty of the two; polyester is the lower-cost option for less exposed installations. Both are a cost premium over anodizing and are quoted per project rather than offered as a default. Hard-coat anodizing is available where a part also serves as a heat-spreading baseplate, but it is rarely specified on inverter housings and is quoted on request. How Do You Machine an Inverter Housing Without Warping? Three controls, applied together, keep the housing within tolerance after machining. Rough, stress-relieve, finish. The housing body is rough-machined with 0.3–0.5 mm stock left on the cover-sealing face and any large flat. It is then sent through a thermal stress-relief cycle (typically 1 h at 350 °C for 6063, slower cooling). Finish machining then removes the released-stress layer to final dimension. Single-fixture machining. The cover-sealing face, mounting holes and cable entries are machined in one setup on a 3- or 4-axis center. Flatness and hole position stay tied to one datum — the machine's own positioning accuracy — instead of accumulating error from re-clamping. Soft jaws and expanding mandrels on hollow sections. A rigid clamp on a thin-walled aluminum housing will pull the wall oval by 0.05–0.10 mm, which is enough to leak. Pie-shaped soft jaws and expanding mandrels spread clamping force around the bore or circumference, so the part holds shape while features are machined. The result, measured on a 1.5 m housing: 0.05 mm flatness on the cover-sealing face, ±0.05 mm on mounting hole positions, and a leak-test pass rate above 99 % on the first article. How Do You Keep an Inverter Housing Weather-Tight After Machining? IP65 is achievable on a CNC-machined aluminum housing when three conditions are met: The cover-sealing face is milled flat to 0.05 mm with surface roughness Ra 0.8 µm or finer. A continuous EPDM or silicone gasket groove is cut in the same setup, so the gasket sits on the same datum as the bolt holes. Cable entries use IP-rated gland plates or compression fittings, not raw drilled holes. We run a 100 % leak-check on every housing lot: pressurize the housing to 30 kPa for 60 seconds, monitor pressure drop. Any drop above 50 Pa rejects the part. For IP67 or higher ratings, we add a second gasket path on the cable-entry plate and re-test at the rated immersion depth. What Does the Workflow Look Like from Drawing to Delivery? Step Activity Typical duration 1. Drawing review STEP / IGES / DWG / PDF checked for extrudability, tolerances, wall thickness and corner radius 1 working day 2. DFM feedback Design-for-manufacturability report with cost-down suggestions (orientation, tolerances, fastener placement) 1–2 working days 3. Extrusion die design & cut H13 die, nitrided, balanced flow; sample extrusions produced on the extrusion press 10–15 working days for a new die 4. Prototyping CNC machining in 3- or 4-axis setup, prototype lot of 1–10 pieces, full inspection report 3–7 working days 5. First-article inspection CMM dimensional check, finish validation on sample parts, IP-rating leak test 2 working days 6. Mass production 100 % in-process audit, full final dimensional and visual inspection, batch inspection report 15–25 days after die approval 7. Packing & delivery Individual wrap, pearl-cotton padding, export carton or seaworthy crate; FOB Shenzhen / Guangzhou (CIF on request) 1–2 working days Material certificates for the aluminum billet (chemical composition and mechanical properties) are supplied with every shipment. Surface-finish thickness records and CMM inspection data are issued on request for OEM customers. Production site: Foshan, Guangdong, China. Die design, extrusion, finishing and fabrication run on one site, and containers load at Shenzhen (Yantian / Shekou) or Guangzhou; that is why we quote FOB Shenzhen / Guangzhou by default, and can also quote CIF to most major ports in Europe, the Americas, the Middle East and Africa on request. Our Santiago office serves customers throughout South America in their own time zone. Get a quote for your inverter housing or optimizer bracket Send a STEP file and your surface finish specification. We will return a DFM review, an itemized quotation and prototype lead time within 24 hours. Request a quote · All CNC Machining Parts · CNC Machining of Aluminum Profiles
Q: What is the MOQ and lead time for a custom inverter housing?
A: Prototyping starts at one piece. Series production minimum order quantity is 500 pcs, sized so a single die run covers the lot. Extrusion die tooling is quoted for the project and depends on the section size and hole pattern. Lead time is 15–25 days after die approval for production orders; prototyping in 3–7 working days from a STEP file. Standard packing is individual wrap in pearl-cotton padding inside export cartons, FOB Shenzhen / Guangzhou, with a seaworthy crate option for full container loads.
Q: Can you machine the housing from a 3D-printed or sand-cast blank instead of extrusion?
A: Yes, on prototype or low-volume runs (typically below 500 pieces) where the die cost of extrusion is not yet justified. We work with 6061-T6 or A356-T6 cast blanks CNC-finished to the same ±0.05 mm tolerance. The surface finish and sealing performance differ from extrusion — cast surfaces are rougher and require additional sealing — so we will flag this in the DFM review if your design is borderline.
Q: Do you supply the cover and the mounting brackets, or only the housing body?
A: Both. We can deliver the full sub-assembly: housing body, CNC-machined cover (matched to the housing face), mounting brackets in 6061-T6, EPDM gasket cut to size, and stainless steel captive screws. As a single supplier we hold tolerance across the parts, which is what makes the IP65 seal reliable.
Q: What is the typical unit cost split for a CNC-finished aluminum inverter housing?
A: On a typical 1.5 m housing at a 500-piece lot: aluminum billet 35–40 %, extrusion processing 15–20 %, CNC machining 25–30 %, surface finish 8–12 %, packing and overhead 5–8 %. Die amortization adds 10–15 % to the unit cost until the die is paid off (typically 5–8 tons of production). High machining time on small features is the single biggest lever for cost reduction — orienting the part so key faces are accessible in one setup typically saves 20–30 % on machining cost.
Q: How do you handle UV and salt-fog exposure on an outdoor housing?
A: Finish selection follows the atmosphere the housing will see. Anodizing is the standard for visible housings at temperate and inland sites. PVDF powder coating over a chromate conversion underlayer is specified for coastal, industrial and desert installations, and for marine or off-shore exposure we add a thicker conversion coating (1.5–3 µm) plus a polyurethane topcoat. Tell us the site, the expected service life and your colour requirement, and we will propose the finish system and the validation it needs.
Q: What file formats do you accept for quotation?
A: STEP (.step / .stp) and IGES for solid geometry are preferred. Parasolid (.x_t) and SolidWorks native (.sldprt) also work. For simpler parts a 2D drawing in PDF or DXF is enough. If only a physical sample exists, our metrology team will reverse-engineer it into an approved production drawing within 2–3 working days before quoting.
Q: Extrusion or billet for an inverter housing?
A: Extrusion when the profile already carries the fins and the wall, billet when the shape is too complex for a die. We quote whichever gives the lower finished cost at your volume.
Q: Do you machine the sealing groove?
A: Yes, along with the cable entries and the mounting bosses, so the gasket sits on a machined face rather than an as-extruded one.
Q: What is the minimum order?
A: Prototypes are quoted individually; series work per drawing.

=== 3030 and 3060 Aluminum Profiles for Packaging Lines, Racks and Machine Frames ===
URL: https://www.linkedalu.com/products/industrial-aluminum/slot-aluminum-profiles/3030-3060-aluminum-profiles-packaging-lines.html
Summary: 30-series T-slot profiles (3030, 3060) for packaging lines, shelving, material-handling carts and machine bases — cut and machined to your BOM, or extruded to your own section.
- Profile Sizes: 3030 (30×30 mm), 3060 (30×60 mm); other 30-series and custom sections on request
- Slot Width: 6 mm (metric 30-series); 4 slots on 3030, 6 slots on 3060
- Weight per Meter: 3030 ≈ 0.9–1.3 kg/m; 3060 ≈ 1.8–2.5 kg/m
- Alloy & Temper: 6063 / 6061 in T4, T5 or T6
- Wall Thickness: From 0.8 mm, set by the section and the load
- Load Guide: 3030 ≈ 50–150 kg at 1 m span, depending on wall thickness and deflection limit
- Standard Length: 2.0 m; cut to length to your BOM
- Surface Finish: Silver anodized AA10 / AA15 standard; black anodized or mill finish on request
- Fabrication: Precision cutting, CNC drilling, tapping M3–M12, end milling, part labelling, packing by assembly zone
- MOQ & Standards: MOQ 500 kg per section, new die or library die; GB/T 5237, ASTM or EN on request
Most framing projects do not need the heaviest profile in the catalogue, and few get away with the lightest one. The 30 mm series sits in that gap: 3030 for uprights, shelf edges and guarding posts, 3060 for beams, conveyor rails and machine bases. We extrude both in 6063 or 6061, in T4, T5 or T6, and machine them to your bill of materials — or cut a die to your own section where the standard geometry does not fit the job. Why the 3030 and 3060 Profiles Fit More Jobs Than 20 or 40 Series The 20-series is light, and it earns its place on a 3D printer frame or a bench-top enclosure. Put a loaded conveyor on it, or a shelf beam carrying a bin, and the frame moves more than the eye tolerates. The 40-series is stiff and durable, and on a guard panel or a cart frame it is more metal than the design needs — you pay for that in weight, freight and cost per metre on every bar in the frame. In between sits the 30-series. A 3030 in a standard wall carries somewhere in the range of 50 to 150 kg at a 1 m span; where it lands inside that band depends on wall thickness and the deflection you are willing to allow. That covers most conveyor side rails, shelf beams, guarding posts and light machine bases, which is exactly where projects either over-specify or under-specify. One rule is worth applying before anything else: choose the section from the deflection limit, not from the catalogue picture. Send us the load, the span and the deflection you can live with, and the quotation will carry the section properties (I and Z) for the profile we propose, so your engineer can run the check rather than take a rule of thumb. 3030 and 3060 Aluminum Profile Dimensions 3030 3060 Cross-section 30 × 30 mm 30 × 60 mm Slot width 6 mm (metric 30-series) 6 mm Slots 4 — one on each face 6 Weight roughly 0.9–1.3 kg/m depending on wall roughly 1.8–2.5 kg/m depending on wall Typical role Uprights, shelf edges, guarding posts, cart frames Conveyor beams, shelf beams, machine bases, longer spans Hardware M6 T-nuts and standard 30-series connectors same A 6 mm slot takes M6 hardware, which is enough for brackets, panel retainers, castors, guarding mounts and cable ducts. Where a joint carries a bending moment rather than a panel load, use the end-face connection into the core bore instead of a side bracket — a side bracket in a slot is a shear connection, and it behaves like one. Because 3060 shares its 30 mm width with 3030, a 3060 beam bolts straight to a 3030 upright on the same nuts and brackets. That is the practical reason to build a frame inside one series: the hardware stays common, so you can mix sections without mixing fastener types. Standard framing length is 2.0 m, cut to your list. Packaging and conveyor lines A packaging line frame has to hold the conveyor at a working height, carry the side rails and the product guides, mount the guarding, the light curtain and the e-stop, and stay square while the line runs. That is a different requirement from a static shelf. The load on a conveyor frame is not static. Cartons drop onto the belt, a diverter fires, a motor starts, and the frame sees that as a repeated impulse rather than a steady weight. A frame that bows 3 mm under a running load puts the belt out of alignment, and the first symptom is usually product tracking to one side rather than anything that looks like a structural failure. Cross-members are the cheapest stiffness available. A mid-span cross-member costs one length of 3030 and two brackets; stepping up a profile size costs extra metal on every bar in the frame. On most conveyor frames the cross-member does more for alignment than the section does. Plan the accessory stack before the BOM. Guard panels, cable ducts, sensors and e-stops all want the same slot faces, and a panel retainer and a bracket cannot share one slot. Working the accessory layout out on the drawing is much cheaper than discovering it with the frame half-built. Reconfiguration is the whole point of a bolted system. Packaging lines change, and a bolted frame comes apart and goes back together with new sections added. A welded frame does not, and that is usually the deciding cost over a five-year horizon. Racking, shelving and material-handling carts Shelf frames are the simplest use of the series: 3030 uprights, 3060 beams, shelf surface on top. It works well, and it fails in two predictable ways. The first is a beam that sags noticeably under a bin, which is a deflection problem rather than a strength problem — the beam size or the span is wrong for the load, and the fix belongs in the design. The second is a cart that rocks because the frame is not square, which is usually a straightness or a cut problem rather than a design fault. Those two symptoms look similar to a buyer and have completely different causes, which is why we ask for the measured deflection when a claim comes in. Cart loading is harder on the frame than the static weight suggests. The castors carry the whole load, and every bump in the floor puts a bending moment into the post rather than a straight compressive one. Where a cart is moved while loaded, size the post for the moving case. One diagonal in the back plane turns a wobbly cart into a rigid one. It is the cheapest fix in any frame, and the one most often left out. Shelf back panels and side panels then mount straight into the slot with panel retainers, no drilling. Machine frames and equipment bases A machine base is judged on how little it moves, and stiffness comes from the section and the geometry rather than from the alloy grade. Moving from 6063 to 6061, or from T5 to T6, raises the yield strength and does almost nothing for deflection, because deflection is governed by the modulus of elasticity, which is essentially the same across them. If a base is flexing, the size of the section is the variable to change. Every connection in a bolted frame is a joint, and joints move. Put the main load path through end-face tapping into the profile core, and keep side brackets for panels, guards and accessories. A frame assembled entirely with side brackets will behave exactly like a frame assembled with side brackets. Leveling feet with a defined thread and a lock nut turn a four-post base into a stable plane on a floor that is not flat. Plan the foot thread at the same time as the post, because the depth of the tapped core has to suit the stud you intend to use. On vibration, one honest note: aluminium does not damp the way cast iron does. Where a machine is genuinely sensitive, mass and a stiff bolted structure help more than a change of profile or alloy, and a really quiet base usually means a concrete or steel sub-frame under an aluminium top frame rather than a heavier aluminium section. Will it fit the hardware you already have? This is the question that arrives most often from a buyer who already runs a framing system: will your 3030 take my nuts and brackets? The honest answer depends on which system. The metric 30 mm grid is a de-facto standard, and the major European framing systems work on the same 30 mm and 45 mm grids with the same standard T-slot connector hardware, so metric 30-series brackets generally interchange. The imperial families are a different grid entirely: an inch-based 1.5 in (38.1 mm) profile with an inch slot is not interchangeable with a metric 30-series section, and a “30 series” label on a supplier’s website does not tell you which of the two you are ordering. To confirm a match we need one of three things: the T-nut you are using, the measured slot opening, or a sample bracket. We check the slot width and the tongue geometry against the die before it is cut, and if it will not fit we say so before the order rather than letting you find out at assembly. If nothing on the market matches what you need, that is the case for your own die. OEM and ODM: your own section instead of a catalogue number OEM — you have the drawing. We extrude your section: your slot geometry, your wall thickness, your core bore. It is machined to your cut list, and every bar is labelled with your part number so your crew builds by the numbers. Bar labels and packing can be supplied as your own private-label frame kit. ODM — you have the load case, not the drawing. Give us the load, the span, the deflection limit and the envelope, and we will propose the section, including slot layout and the wall thickness that meets it. We have done this for conveyor, racking and machine-base frames, and it is usually faster than starting from a catalogue. Dies are cut in-house, so tooling lead time sits with us rather than with a third party. MOQ is 500 kg per section, whether the section runs on a die already in our library or a new one is cut for it. We send a length from the first pressed billet as a sample before you commit to the run, which for a framing system is the only way to confirm the slot before several tonnes of profile arrive. Extrusion is invoiced on weight, and a ±10 % tolerance on total weight is normal for custom work, so a 500 kg order can arrive between roughly 450 kg and 550 kg. We quote the weight per metre up front so the reconciliation on arrival is arithmetic rather than a dispute. On length and freight: 2.0 m is the standard framing length and bars are also cut to your list. A 20 ft container takes up to 5.85 m, so anything longer ships in a 40 ft or comes cut to fit. On finish: silver anodized in AA10 or AA15 is the standard for frame profiles and the most colour-stable; black anodized is available where a machine or a cleanroom calls for it, and mill finish for structure that will not be seen. Every bar in one order is anodized in a single batch, so legs and beams match. Mill test certificates covering composition, temper and mechanical properties are issued with every lot. Manufacture is to GB/T 5237, and to ASTM or EN on request.
Q: Which profile should I use for a conveyor frame — 3030 or 3060?
A: 3030 for uprights, guarding posts and the shorter members; 3060 for the beams that span. A 3060 shares the 30 mm width and the same hardware, so the two mix freely in one frame. Send the load, the span and the deflection limit and we will confirm the section with its section properties.
Q: Will your 3030 work with the T-nuts and brackets I already use?
A: If your existing system is on the metric 30 mm grid, generally yes — the metric 30-series is a de-facto standard and shares standard T-slot connector hardware. Inch-based 1.5 in (38.1 mm) systems are a different grid and are not interchangeable. Send us your T-nut, the measured slot opening, or a sample bracket and we will confirm before the die is cut.
Q: What load can a 3030 carry over 1 m?
A: Roughly 50 to 150 kg, depending on wall thickness and the deflection you allow. That range is wide because deflection is the governing limit, not strength. Give us the load and the deflection limit and we will return the section properties for the profile we propose.
Q: Can you extrude a custom slot profile to our own drawing?
A: Yes, that is our OEM line. You supply the section drawing and the slot geometry; we cut the die in-house, run a sample length from the first billet and machine to your cut list. MOQ is 500 kg per section, the same for a new die as for a section already in our library.
Q: What is your MOQ and can we see a sample first?
A: 500 kg per section. A sample length from the first pressed billet is sent before you commit to the full run — with a framing system that is the practical way to confirm the slot and the fit of your hardware.
Q: What is the difference between 3030 and 3060?
A: Same 30 mm slot system, different section depth. 3060 gives roughly twice the bending stiffness in one direction, which is why it turns up on conveyor spans and gantry uprights.
Q: Will 3030 profile take the fasteners I already use?
A: If they are standard 30-series T-slot hardware, yes. Send a sample or the supplier part number and we check the slot before quoting.
Q: Can you extrude a custom 30-series section?
A: Yes. If a catalogue 3030 or 3060 does not fit, we cut a die to your section and you get your own profile instead of a catalogue number.

=== Aluminum Handrail and Guardrail Profiles ===
URL: https://www.linkedalu.com/products/architectural-aluminum/guardrail/aluminum-handrail-guardrail-profiles.html
Summary: Custom extruded aluminium handrail and guardrail profiles — top rails, posts, balusters and wall-mounted handrails for balconies, stairs and terraces, machined to your drawing.
- Alloy & Temper: 6063-T6 / 6061-T6
- Profile Type: Handrails, posts, balusters, infill rails, wall-mounted handrails
- Wall Thickness: 0.8 mm and above, set by section and load
- Tolerance: GB/T 5237
- Surface Finish: Anodizing AA10 / AA15 (AA20 on request)
- Length: 6.0 m standard, cut to project length
- Fabrication: Cut to length, mitres, drainage holes, tapping, notching, label to drawing
- MOQ: 500 kg per section (new die or existing die)
- Weight Tolerance: ±10 % on total order weight
- Standards: GB/T 5237; ASTM or EN on request
Linkedalu Metal Group extrudes aluminium handrail and guardrail profiles for balconies, stair flights, terraces, walkways and pool decks: top rails, wall-mounted handrails, posts, balusters and infill rails, cut, drilled and tapped to your drawing. This page covers the railing systems that do not use glass. If your project clamps laminated glass in a base shoe, our glass balustrade page is the closer match. Handrail, guardrail, balustrade — three jobs, three different sections The three words get used interchangeably in enquiries. They should not be. A handrail is the part a person grips, sized by hand geometry and grip load. A guardrail is the barrier that stops a fall at a level change, sized by a code line load and a deflection limit. A balustrade is the whole assembly: top rail, posts, balusters and infill. The most common mistake we see is a handrail section quoted for a job that needs a guardrail. A 38 mm handrail tube is comfortable to hold and will not pass as a guardrail post on a 6 m span at any wall thickness. Decide which job the section has to do before choosing anything else. Component Sized by Typical section we extrude Handrail (grip) Hand span, grip comfort, point pull 38 mm or 50 mm round; 40 × 60 mm shaped oval; flat-bar wall rail Guardrail top rail Line load and deflection over the post spacing 50 mm round tube, 2.0 mm wall; 60 × 40 mm box; shaped top rail with a screw channel Post Cantilever moment from the line load; base fixity 60 × 60 mm or 80 × 40 mm multi-chamber; 100 × 50 mm with an infill slot Baluster / infill Sphere-gap rule, picket or panel spacing 25 × 25 mm; 30 × 30 mm; 40 × 20 mm flat oval; 50 mm flat bar Wall-mounted handrail Grip and bracket pull-out 38 mm or 50 mm round with a bracket slot; flat back-plate section The load a guardrail has to carry Codes describe a guardrail with two numbers: a uniform line load along the top rail, and a concentrated load at any point. The IBC, for example, puts 0.73 kN/m uniform or 0.89 kN concentrated on the guardrail of a dwelling; assembly occupancies and vehicle areas are higher. Gulf and Latin American codes set their own figures, and the one that governs is the one on your permit — not the one in a supplier’s catalogue. Infill carries load too, and on an open balcony it is also a sail for wind. Above roughly the fourth floor in an exposed location, wind on the infill usually governs the post rather than the line load. Deflection picks the section, not stress. A guardrail almost never fails on strength — the aluminium has strength to spare. It fails on movement, because a barrier may flex a little and not much: 30 mm at the top of the post is a common cap, and some codes allow H/24 or more. Deflection grows with the cube of the span and falls with the section’s second moment of area. Double the post spacing on the same post and it does not move twice as much — it moves eight times as much. That is why post spacing cannot be answered without the section properties, and why we publish I and Z with every quotation so your engineer can run the check rather than take a rule of thumb. The codes your inspector will name. Brazil’s ABNT NBR 14718 requires a guarda-corpo wherever the level change exceeds 0.60 m, at 1.10 m minimum above the finished floor and 1.20 m on accessible roofs. Dubai and Abu Dhabi require balcony balustrades in vertical rods rather than horizontal rails, so children cannot climb them. Saudi projects work to the Saudi Building Code. Industrial guardrails follow EN ISO 14122-3 at 1,100 mm. Send us the code and the design load with the enquiry and the section we propose arrives with the check already run. Hot, humid and coastal sites In Gulf and tropical sun a dark matt handrail runs 20 to 30 K above ambient. That is uncomfortable to grip and can fall foul of accessibility requirements, and it is not fixed by making the section thicker. Light finishes reflect more and stay cooler. Where the architect has fixed a dark colour, a polyamide thermal break — separating the sun-heated outer skin from the fixing web — is the usual answer. It is not part of our standard handrail range; we run it on request where a project’s temperature requirement justifies the die, and we will say plainly when a lighter finish solves the same problem for less. Fasteners and the 0.5 V rule. Stainless steel and aluminium form a galvanic couple, and in a damp coastal detail the aluminium is the part that disappears — a bare section in direct contact with a stainless fastener can lose measurable metal within 18 to 24 months. It is designed out, not maintained out: nylon or EPDM isolating washers and sleeves at every stainless fastener; no stainless bearing directly on bare aluminium; a base plate sealed at the perimeter but with a weep path so water cannot stand in the post foot; cut ends and drilled holes kept clear of standing water and touched up on site. A post foot sitting in a puddle will corrode whatever is done above it. On pool decks and beachfront work, add a freshwater wash to the maintenance schedule — salt left on the surface is the slow version of the same failure. Baluster and Glass Balustrade Infill Design Two numbers cover most residential railing rules: no opening in the infill may pass a 100 mm sphere, and the barrier must reach at least 1.10 m above the finished floor. Measure the sphere rule at the widest point of the opening — including the gap under the bottom rail and any diagonal opening formed at a post, which is measured on its widest dimension rather than its side. Vertical infill is the safer default, and the required one for balconies in Dubai and Abu Dhabi: horizontal rails read as a ladder to a child. Where a project genuinely needs the horizontal line across a long terrace, set the spacing and any intermediate rails so the assembly is not climbable, and record the decision in the design rather than settling it on site. Infill Where it works Watch out for Vertical aluminium balusters Balconies, stairs, terraces — the lightest option Set the sphere gap correctly; fewer thicker balusters read cleaner than many thin ones Flat-bar or oval pickets Where a solid, private look is wanted More metal, more weight, higher cost per metre Perforated or slotted aluminium panels Car parks, plant enclosures, high-wind sites Wind load on the panel usually governs the post; the sphere rule applies to the apertures Stainless cable Views, terraces, feature stairs Cable needs tensioning maintenance and correct fittings; anchor loads are high Alloys, wall thickness and finish 6063-T6 covers handrails, balusters, infill and cover caps, and 6061-T6 is what we run for base plates, brackets and industrial guardrails that are drilled or tapped. Higher-strength 6005A-T6 is not our standard alloy for handrail sections; where a post or a long cantilever genuinely needs more stiffness than 6063 gives, tell us the span and the design load and we will look at it for that section. Wall thickness starts at 0.8 mm and is set by the section and the load it carries. Where a section has to be tapped, we thicken the wall locally in the die so the thread has material to bite into. Manufacture is to GB/T 5237, and to ASTM or EN on request, with mill test certificates giving composition, temper and mechanical properties. Finish is covered in detail elsewhere on this site, so in short: anodizing AA10 and AA15 are what we run as standard, with AA20 on request. Powder coating and PVDF are available but carry a substantial cost premium and are quoted only when a project specifies them. One point worth making, because it is the most expensive mistake we see: trimming a post wall saves a few percent of metal and cuts the section’s stiffness enough to change the maximum post spacing or the permitted height. If a tender has to come down, take it out of the infill count, not out of the post. Die, MOQ, machining and packing We cut dies in-house. MOQ is 500 kg per section, whether it runs on a die already in our library or a new one is cut for it. If you are evaluating a design, ask for a sample length from the first pressed billet before committing to the run. Extrusion is invoiced on weight, and a ±10 % tolerance on total weight is normal for custom work, so a nominal 500 kg order can arrive between roughly 450 kg and 550 kg. We quote the section weight per metre up front so the reconciliation on arrival is arithmetic rather than a dispute. Tell us if your order has to be firm. Bars ship in whatever state your installation sequence needs: mill finish cut to rough length, cut to a finished-length list, or fully prepared with mitres, drainage holes, tapped fixing points, countersinks and notches. Notching and drilling are cheap at our end and expensive on a balcony. Send a DXF or PDF cut list and we machine to the drawing, not to a description. On packing: a 20 ft container takes up to 5.85 m, so 6.0 m bars ship in a 40 ft or 40 HQ, or we cut them to your list before packing. Decide this early — it changes the cut list, the scrap allowance and the price. Coated bars are sleeved and interleaved, bundled with the ends protected, and labelled by assembly zone so a crew opens one bundle per balcony or per stair flight instead of sorting a mixed pile on the slab. Transit damage to the coating is the most common claim on a railing shipment, and most of it is avoidable with proper interleaving and lifting. Questions that arrive with the enquiry Which alloy — 6063, 6005A or 6061? Handrails, balusters and infill run in 6063-T6 as standard, and base plates and drilled brackets in 6061-T6. 6005A-T6 is not our standard handrail alloy; if a post or cantilever needs more than 6063 gives, send the span and the design load and we will discuss it for that section. The screws strip when we tap the post. Why? Thread engagement. A tapped thread in aluminium needs about 1.5 times the screw diameter in depth to reach its rated load, so an M8 screw needs roughly 12 mm of tapped depth — more than a thin-wall post can offer. The answer is designed in: a heavier local wall, an internal boss thickened in the die, or a through-bolt with an isolation sleeve. We mark tapping zones on the section drawing. Adding wall thickness afterwards is not possible. How far apart can the posts be? It comes from the section, not from habit. Give us the line load, the post height above the fixing and the base condition — cast into the slab, surface-mounted base plate, or bolted to a steel embed — and we return the maximum spacing that holds the deflection limit, together with the anchor pull-out the base needs. Between 1.2 m and 1.5 m covers most residential balcony work. How do we stop corrosion at the base plate? Isolate the aluminium from any steel or stainless, seal the plate perimeter to the slab, and give the water a way out. Galvanic corrosion needs a metal pair and an electrolyte; crevice corrosion needs standing water. Remove either and the base lasts. Typical applications Balcony and terrace guardrails Stair, landing and ramp handrails Wall-mounted corridor handrails Pool-deck and beachfront railings Walkway and mezzanine edge protection Industrial and plant guardrails to EN ISO 14122-3
Q: What is the difference between a handrail and a guardrail?
A: A handrail is the member a person grips, sized for hand geometry and grip load. A guardrail is the barrier that prevents a fall, sized by a code line load and a deflection limit. A balustrade is the complete assembly of top rail, posts and infill. A section quoted for one job will often not satisfy the other.
Q: Which alloy should I use for a balcony guardrail?
A: 6063-T6 for handrails, balusters and infill — it extrudes to a clean surface, takes anodizing evenly and has strength to spare for members that are not carrying the barrier. 6061-T6 for base plates, brackets and industrial guardrails that are drilled or tapped. For a post or cantilever needing more stiffness than 6063 provides, send the span and the design load.
Q: How far apart should guardrail posts be?
A: It follows from the section properties and the design load, not from a fixed rule. Give us the code line load, the post height and the base condition, and we will return the maximum spacing that holds the deflection limit together with the anchor pull-out required. Between 1.2 m and 1.5 m covers most residential work.
Q: Can you cut, drill, tap and notch to our drawing?
A: Yes. Send a DXF or PDF cut list and the bars arrive cut to finished length with mitres, drainage holes, tapped fixing points, countersinks and notches in place, labelled by assembly zone. A 20 ft container takes up to 5.85 m, so 6.0 m bars ship in a 40 ft or are cut to 5.85 m or less.
Q: What is your MOQ, and does a new die change it?
A: 500 kg per section. MOQ does not change whether the section runs on a die already in our library or a new die is cut for it. Lead time is confirmed after die and sample approval, and a sample length from the first billet is available before you commit to the run.
Q: Do you make glass balustrade profiles?
A: Yes. Glass balustrade work runs on the same dies as guardrail: a base shoe, a top rail and the posts. Send the glass thickness and the span, and we match the channel and the clamping detail to it.
Q: Which section do I need for a balcony railing?
A: It depends on the span, the fixing points and the infill. Send the balcony layout and the height you are working to; we size the post and top rail from the load rather than from a catalogue guess.
Q: What is the minimum order for handrail profiles?
A: 500 kg per section, whether or not a new die is required. Posts, rails and balusters can be consolidated into one shipment.

=== Aluminum Garage Rolling Shutter Profiles ===
URL: https://www.linkedalu.com/products/architectural-aluminum/windows-doors/aluminum-garage-rolling-shutter-profiles.html
Summary: Custom 6063-T5 aluminum rolling shutter profiles for garage doors — interlocking slats, guide rails and bottom bars engineered for quiet operation, smooth travel and long service life, supplied as cut, brush-fitted and labeled kits to your drawing.
- Alloy & Temper: 6063-T5 for slat, guide rail and bottom bar sections
- Slat Wall Thickness: 1.0 / 1.2 / 1.4 / 1.6 / 2.0 mm
- Slat Pitch (Height): 55-140 mm depending on door size and coil diameter
- Sound Reduction (Rw): 15-20 dB single-layer; 25-35 dB foam-filled double-layer, measured per ISO 717-1
- Guide Rail Section: 70 / 80 / 100 / 120 mm width; 2.0-2.5 mm wall with brush strip slot
- Bottom Bar Section: 40 x 90 mm with integrated EPDM weather seal slot and plastic end caps
- Hook Geometry: Hook lip width held to +/-0.15 mm; interlock clearance 0.3-0.6 mm
- Extrusion Tolerances: GB/T 5237.1 / EN 12020-2; straightness <= 0.8 mm per 1000 mm; cut to +/-0.5 mm for door kits
- Surface Finish: Anodizing AA10 / AA15 / AA20; powder coating to RAL with delta E <= 1.0 batch-to-batch
- Standards & Documentation: EN 16730 / EN 13241-1 door-set data; MTC to EN 10204 3.1; CE marking documentation
Custom Aluminum Profiles for Garage Rolling Shutters Rolling shutter slats, guide rails and bottom bars are extruded in 6063-T5: slat walls 1.0–2.0 mm, slat pitch 55–140 mm, guide rails 70–120 mm wide. Single-layer slats reach Rw 15–20 dB; foam-filled double-layer 25–35 dB. 500 kg per profile. A new aluminum rolling shutter that opens like a gunshot is a problem with the profile, not the operator. The owner hears "snap, snap, snap" as the curtain rolls up. The installer blames the motor. The buyer blames the supplier. Nobody looks at the slat hook geometry, the brush seal in the guide rail, the wall thickness tolerance on the curtain, or whether the header beam is level across the opening. These four details determine whether a rolling shutter runs quietly for fifteen years or starts clattering after season one. Linkedalu Metal Group Co., Ltd supplies custom extruded aluminum profiles for garage rolling shutter doors — interlocking slats, guide rails and bottom bars — engineered to project specification for quiet operation, smooth travel and long service life. Sections are extruded in 6063-T5 to GB/T 5237, EN 12020-2 and EN 16730 (the European door-set standard), with mill test certificates per EN 10204 3.1 shipped with every order. We currently ship to 50+ countries across Europe, the Americas, the Middle East, Africa, Asia and Oceania. Three parts make a rolling shutter — and three parts make the noise What the homeowner actually hears — and where it comes from A rolling shutter is three parts, not one. The curtain (the interlocking slats), the guide rails (vertical channels on either side of the opening), and the bottom bar (the closing edge that meets the floor). Each contributes to the sound the door makes. Part What it has to do Where it goes wrong Curtain (slats) Interlock cleanly; coil evenly around the barrel; flex without permanent set Hook geometry too tight → slats lock against each other during coiling Guide rails Hold the curtain aligned; seal against wind, dust, light and noise Brush strip missing or undersized → curtain metal-on-metal contact Bottom bar Seal against the floor; absorb impact on close EPDM seal undersized → wind-driven rain and dust enter Most "noisy shutter" complaints trace back to one of three causes: slat hook geometry that doesn't flex on coil, guide rails without the right brush profile, and a bottom bar without an EPDM weather seal. The profile is the cheapest place to fix all three at once. The alloy and temper that makes a shutter quiet Why 6063-T5 is the standard for rolling shutters Rolling-shutter duty is a moderate-stress, high-cycle, surface-critical application. The curtain opens and closes tens of thousands of times over its service life; the surface is visible on every building facade; and the slat must flex on coil without permanent set. 6063-T5 is the alloy-temper combination used across the industry for these reasons: Extrudability — 6063 flows cleanly into thin walls and complex interlocking hook geometry, including the curved hook lips that are hard to fill in 6061. Surface finish — 6063-T5 anodizes uniformly and holds powder-coat adhesion well, so the same section can be finished to match any RAL colour reference. Strength — Tensile ≥ 160 MPa, yield ≥ 110 MPa (per GB/T 5237.1 / EN 755-2 minimums). Plenty for the curtain duty; not enough for the barrel axle or operator bracket (those go in steel). Weldability — Good; slats are usually mechanically interlocked rather than welded, but the bottom bar and guide rail are often welded to reinforcement plates in assembly. For coastal and high-corrosion sites, 6063-T5 with AA20 anodizing or PVDF top-coat powder is the standard. 6061-T6 is not typically used for the curtain itself (harder to extrude into thin walls, harder to anodize) but does show up in the barrel axle bracket and operator mounting plate where higher strength matters. Mechanical properties that matter for slat duty Property 6063-T5 minimum (GB/T 5237.1 / EN 755-2) Practical range for slats Tensile strength Rm ≥ 160 MPa 160–210 MPa Yield strength Rp0.2 ≥ 110 MPa 110–160 MPa Elongation A50 ≥ 8 % 8–12 % Brinell hardness ~ 60 HB 55–70 HB Anodizing response Excellent (uniform, bright) Standard Surface roughness after extrude Ra 0.8–3.2 µm Depends on die finish Slat profile engineering — interlocking, hook geometry, sealing Single-layer slats for residential and light commercial doors Single-layer is the workhorse. One extruded aluminium section, one interlock, one brush seal per guide rail. Wall thickness typically 1.0 / 1.2 / 1.4 / 2.0 mm; pitch (slat height) typically 55 to 100 mm. Sound reduction Rw is in the 15–20 dB range when properly sealed — quieter than a standard glass window, comparable to a domestic interior wall. The slat hook geometry is the engineering that makes or breaks the door. The hook has to: Lock firmly when the curtain is in the closed position (security). Flex without permanent set as the curtain coils around the barrel (cycle life). Slide smoothly along the guide rail brush without catching (noise). A hook that's too tight locks firmly but cracks after 5,000 cycles. A hook that's too loose opens quietly but rattles in wind and can be pried open. The right answer is in the middle, and it's a die-design decision we make before cutting steel. Double-layer foam-filled slats for sound and thermal Where the spec calls for sound reduction Rw ≥ 25 dB or thermal insulation (often coastal villas, premium residential, or commercial buildings adjacent to busy roads), double-layer slats are the standard. Two aluminium profiles are coextruded or mechanically assembled, with a polyurethane foam core in the cavity between them. Sound reduction moves to the 25–35 dB range; thermal performance improves by ~25 %. Pitch height, wall thickness and how they trade off Pitch (slat height) Typical wall Typical use 55–65 mm 1.0–1.2 mm Small residential doors, tight coil 75–90 mm 1.2–1.4 mm Standard residential and light commercial 95–110 mm 1.4–1.6 mm Larger residential, small commercial 120–140 mm 1.6–2.0 mm Commercial / industrial, large openings Wider pitch + thinner wall = more material cost per door (the wider extrusion needs slower press speed and larger container in the billet log). Narrower pitch + thicker wall = stiffer curtain that won't coil as tightly and may need a larger barrel. We work through this trade-off on your drawing before the die is cut. Guide rail and bottom bar — the parts that make it quiet Guide rail section, brush strip and EPDM seal The guide rail is the section the curtain slides against on every open and close. Three details matter: Section dimensions — typically 70 / 80 / 100 / 120 mm width, 2.0–2.5 mm wall. The rail section must match the curtain hook geometry within ±0.2 mm; otherwise the curtain binds. Brush strip — a polyprop or nylon filament brush inserted into a slot in the rail's inner edge. The brush keeps the curtain off the metal rail, seals light and wind, and absorbs the noise of curtain travel. A correctly specified brush is the difference between a quiet door and a noisy one. Anchoring — the rail must mount to a structurally sound surface (concrete, masonry, structural steel). It cannot mount to plasterboard alone; the door will distort, the curtain will bind, the noise will follow. Bottom bar, EPDM weather seal and end caps The bottom bar is the closing edge of the curtain. Three details: Section — typically 40×90 mm aluminium extruded bar with an integrated slot for the EPDM weather seal. The bar stiffens the bottom edge against wind and impact. EPDM weather seal — sits in the bottom bar's T-slot, compresses against the floor on close. Prevents wind-driven water, dust and noise ingress; provides the second line of acoustic insulation behind the brush strip. Plastic end caps — close off the bar at both ends, prevent lateral curtain movement, keep the bar from marking the side guides. Alignment tolerance — why the header matters This is the most-overlooked field installation detail. The header (top guide / barrel support beam) must be level across the opening within ±3 mm over the full width. If it's not, the curtain coils onto the barrel at an angle, the slats wedge against each other, and the door makes a "snap, snap, snap" as it opens. The profile isn't the problem; the header is. We supply the profile to spec; the installer is responsible for the header. The two have to meet on site. Tolerances, standards and what they actually hold Per-profile extrusion tolerance per GB/T 5237.1 / EN 12020-2 Dimension Standard tolerance Slat pitch (height) ± 0.2 mm for small slats; ± 0.3 mm for slats > 80 mm Wall thickness ± 10 % of nominal Hook lip width ± 0.15 mm (functional — affects interlock) Guide rail width ± 0.3 mm Straightness ≤ 0.8 mm per 1000 mm Length — standard cut ± 1 to ± 5 mm Length — precision cut (door kits) ± 0.5 mm Door-set testing per EN 16730 / EN 13241-1 EN 16730 is the European standard specifically for rolling shutter doors without counterbalance. EN 13241-1 is the broader industrial / commercial door standard. Both call out: Mechanical endurance (typically 25,000 cycles for residential; 100,000+ for commercial). Wind load class (Class 1–5, with Class 2 ≈ 500 Pa for typical residential). Sound reduction Rw (lab-measured per ISO 717-1). Safety edge and anti-crush protection. We supply profiles that meet the dimensional requirements of EN 16730. The door-set certification (CE marking under EN 13241-1) is the assembler's responsibility; we provide the test data on the profile that supports the certification. Sound reduction (Rw) and how it is measured Configuration Sound reduction Rw Single-layer slat, brush seal only 15–20 dB Double-layer foam-filled slat, brush seal 25–30 dB Double-layer foam-filled + acoustic bottom seal 30–35 dB These are lab-measured figures under ISO 717-1. Real-world reduction depends on the opening perimeter, the surrounding wall construction, and whether the door is fully closed. Surface finish — anodizing, powder coating, RAL colours Anodizing for coastal and high-UV sites 6063-T5 anodizes uniformly — the standard Class AA10 for inland, Class AA15 / AA20 for coastal and high-UV sites. Anodizing is integral to the substrate (not a coating that peels), so it survives the curtain coiling and uncoiling for the full service life. Powder coating for the widest RAL palette For projects where colour match to the surrounding facade matters — RAL 7016 anthracite, RAL 9005 black, RAL 9016 white, custom — polyester or PVDF powder coating is the standard. Specify the gloss level (matte is the residential default) and we hold ΔE ≤ 1.0 batch-to-batch. ΔE batch control across a multi-shipment project On multi-phase rollouts (e.g., a residential development with 200 doors across 4 phases), we run all phases on the same coating line and verify every batch with a digital colorimeter. The ΔE between the first door in phase 1 and the last door in phase 4 stays inside your spec, not inside our hope. How a rolling shutter profile order moves through the mill You send the drawing — slat pitch, wall thickness, hook geometry, guide rail section, bottom bar section, finish, fabrication list. We review extrudability, check hook geometry for cycle life, propose alloy/temper and finish. New die or reused die; locked to a single billet batch. Extrusion → straightening → cut-to-length → brush strip insertion (if ordered) → end cap installation → finish → labeling. MTC (EN 10204 3.1) issued to GB/T 5237, EN 12020-2 with measured mechanical properties, chemical composition and coating parameters. Packed in kits per door or per project phase, with bundle labels traced to billet batch and coating run.
Q: Why does my new aluminum roller shutter make a snapping sound every time it goes up?
A: The four most common causes, in order: (1) slat hook lips that are too tight and wedge against each other as the curtain coils; (2) guide rails without the correct brush strip, so the curtain is metal-on-metal against the rail; (3) a bottom bar without an EPDM weather seal, so the closing impact transmits to the structure; (4) a header beam that isn't level across the opening, so the curtain coils at an angle and the slats bind. The first three are profile issues (the right extruder fixes them); the fourth is an installation issue (the right installer fixes it). Send us a short video of the noise and a photo of the installed header; we can usually tell within 30 seconds which one it is.
Q: Will an aluminum roller shutter actually reduce noise, or is that marketing?
A: It depends on the slat configuration. A single-layer slat with brush seal typically delivers Rw 15-20 dB - comparable to a standard insulated interior wall and quieter than a domestic glass window. A double-layer foam-filled slat with brush and acoustic bottom seal delivers Rw 25-35 dB, closer to a heavily insulated cavity wall. Lab measurements are per ISO 717-1; real-world reduction also depends on the perimeter seal and the surrounding wall construction. We publish the Rw figure on the MTC for the configuration we supply, not a generic noise reduction claim.
Q: How do I specify slat hook geometry so the curtain coils cleanly and lasts 25,000 cycles?
A: Three numbers on the drawing do most of the work. The hook lip width (the overlap when two slats interlock) - typically 8-12 mm per side, held to +/-0.15 mm; too tight locks but cracks on coil, too loose rattles in wind. The hook lip thickness - typically 1.2-1.6 mm; thicker = stronger but stiffer coil. The interlock clearance - the gap between slats when fully engaged; ~0.3-0.6 mm is the working range for clean coiling. Beyond geometry, the alloy and temper matter: 6063-T5 is the industry standard for residential shutters because it extrudes cleanly into thin hook walls and flexes without permanent set for the design cycle count.
Q: Does the brush strip in the guide rail make that much difference?
A: Yes. The brush strip is what separates the curtain from the metal rail on every open and close. Without it, the curtain rides directly on the aluminium rail, the metal-on-metal contact is the dominant sound the door makes, and the curtain coating wears against the rail within a few thousand cycles. With the correct brush strip (polyprop or nylon filament, ~6-8 mm pile height, inserted into a slot in the rail's inner edge), the door runs quieter, seals better against wind and dust, and the curtain lasts longer. The brush is the cheapest component in the door; it does the most for perceived quality.
Q: When is a single-layer slat enough, and when do I need double-layer foam-filled?
A: Single-layer is the standard for typical residential and light commercial doors. Use it for openings up to ~6 m wide and ~3 m high, with normal sound and thermal expectations. Move to double-layer foam-filled when the spec calls for sound reduction Rw >= 25 dB (adjacent to busy roads, premium residential, hotels), thermal insulation contribution (coastal villas, energy-efficient buildings), or larger openings where the additional curtain stiffness helps the door run straight. Foam-filled slats cost roughly 30-50% more per meter than single-layer and need a slightly larger coil barrel, but they're the right answer where the spec demands it.
Q: What documents ship with a rolling shutter profile order, and which countries do you export to?
A: A mill test certificate (EN 10204 3.1) with measured mechanical properties, chemical composition and coating parameters, issued to GB/T 5237, EN 12020-2 as the project requires. Test data on the slat profile that supports EN 16730 / EN 13241-1 door-set certification by the assembler. CE marking documentation and Declaration of Performance if the door is for the European market. CIQ, C/O, Form A for non-European destinations. We currently ship to 50+ countries across six continents - Europe, the Americas, the Middle East, Africa, Asia and Oceania. ISO 9001 and ISO 14001 certified.
Q: Do you supply slats, guides and bottom bars together?
A: Yes. The slat, the guide and the bottom bar normally run as one family so the interlock clearance is set at the die.
Q: Which alloy for shutter slats?
A: 6063-T5 for the slat and the guide. The section is light and the extrusion has to hold the interlock detail cleanly.
Q: What is the minimum order?
A: 500 kg per section, whether or not a new die is required.

=== Architectural Curtain Wall Profiles ===
URL: https://www.linkedalu.com/products/architectural-aluminum/curtain-walls/architectural-curtain-wall-profiles.html
Summary: Engineered aluminum curtain wall framing — mullions, transoms, pressure plates, cover caps and structural thermal break suites — extruded to your shop drawings in 6063-T5 and 6063-T6.
- Alloy & Temper: 6063-T5 / 6063-T6
- Profile Type: Mullions, transoms, pressure plates, cover caps, thermal break suites
- Wall Thickness: 1.2 mm - 6.0 mm
- Tolerance: GB/T 5237.1 high-precision and ultra-high-precision class
- Surface Finish: PVDF 3-coat (approx. 30 um total), polyester powder 60-80 um, anodizing Class AA10 / AA15 / AA20
- Length: 6.0 m - 7.0 m standard; longer mill lengths on project review
- Fabrication: Miter sawing, CNC bolt-hole drilling, milling, tapping, drainage slotting
- MOQ: 500 kgs
- Lead Time: Die and sample approval first, then production scheduling confirmed at order
- Standards: GB/T 5237, EN 755-9, ASTM B221
Short answer. Stick-built and mid-rise unitized curtain wall profiles — mullions, transoms, pressure plates and cover caps — are extruded in 6063-T5/T6 with walls from 1.2 mm to 6.0 mm and mill lengths of 6.0–7.0 m. Thermal break, CNC drilling and tapping run in-house in Foshan, minimum 500 kg per profile, FOB Shenzhen or Guangzhou. Mullion and Transom Sections for Mid-Rise Facades Curtain wall mullions, transoms, pressure plates and cover caps are extruded in 6063-T5/T6 with walls from 1.2 mm to 6.0 mm and mill lengths of 6.0–7.0 m, then cut and machined to your shop drawing. 500 kg per profile; die and sample approval comes before production scheduling. Linkedalu Metal Group Co., Ltd has supplied architectural facade systems for over two decades, and curtain wall framing is the core of that work. We extrude the full component matrix of a curtain wall system — vertical mullions, horizontal transoms, exterior pressure plates, snap-on cover caps and structural thermal break suites — as one synchronized profile package from your shop drawings. Because every die, billet batch and coating run is matched to a single project, your facade reaches site with no color batch variation, no assembly friction between sections and no mismatch between the alloy the engineer specified and the alloy the mill shipped. Pressure Plates, Cover Caps and Corner Sections A curtain wall is only as good as the fit between its parts. We supply the whole set, not a subset: Profile class Structural and functional role Cross-section features Mullions (vertical frames) Primary structural members absorbing wind load and dead load Deep multi-cavity sections with high moments of inertia Transoms (horizontal frames) Carry glass dead load and transfer it to mullions Interlocking geometry with integral glazing register Pressure plates Clamp glazing and weather gaskets to the frame Screw-fixed, matched to mullion and transom faces Cover caps Conceal fixings and finish the visible facade line Snap-fit, profile-matched, color-batch controlled Thermal break assemblies Interrupt heat flow between inner and outer frame PA66+GF25 polyamide strips, mechanically crimped Groove Tolerance ±0.1 mm and What Moves It Our die engineers do more than copy a section. We check the moment of inertia of a proposed mullion against your wind load and deflection limits, then redistribute metal across the cross-section — adding wall thickness where bending stress peaks and shaving non-structural material where it does not, which lowers weight and cost without touching structural performance. Section tolerances are held to the high-precision or ultra-high-precision class of GB/T 5237.1, and standard extrusion length runs 6.0 to 7.0 m, with longer mill lengths reviewed case by case. 6063-T5 vs 6063-T6 for Mullions 6063-T5 is the standard commercial choice for curtain wall framing: it extrudes cleanly, anodizes evenly and carries adequate strength for typical bay spans. Where the section is a primary structural member under high wind loading, we move to 6063-T6, which raises yield strength for the same geometry. The pressing alloy is selected once, against the loads and the standards that govern the project, so the finished frame behaves as the calculation assumed. Anodising AA10 and AA15 on Facade Profiles Facade finishes have to survive decades of UV and weather, so we apply architectural coating systems rather than decorative ones. PVDF is available in two-, three- and four-coat systems, typically around 30 um total build over primer; polyester powder coating runs 60 to 80 um as standard, extendable to 100 um for high-wear locations; anodizing is offered in Class AA10, AA15 and AA20 depending on climate. Coating line parameters and billet batches are locked per project and checked with digital colorimeters so later deliveries match the first. Thermal Break Assembly and CNC Fabrication In-House For green building codes we run thermal break insertion in-house, crimping glass-reinforced polyamide strips into the aluminum section to deliver the shear strength and insulation performance the assembly needs. Downstream, our CNC division handles fixed-length miter sawing, connector pin milling, drainage slotting, bolt-hole drilling and tapping. Delivering pre-machined profiles removes a large share of site fabrication error and field labor cost. Stick-Built and Mid-Rise Applications Stick curtain walls — field-assembled grids built from precision-cut mullions and interlocking transoms. Unitized curtain walls — factory-assembled interlocking frames engineered for rapid crane installation on tall buildings. Point-supported and skylight systems — heavy-duty large-span sections and integrated drainage gutter profiles for atria and glass roofs. Mill Certificates and Container Loading Every order leaves with mill test certificates for alloy, temper and coating, and packing lists tied to bundle labels so each cut length can be traced back to the billet batch and coating run it came from. Raw material is tracked against GB/T 5237, EN 755-9 and ASTM B221 so a single material lot can be documented whichever standard the project specification follows.
Q: Do you supply a complete curtain wall profile package or only the mullions?
A: We extrude the full component matrix: vertical mullions, horizontal transoms, exterior pressure plates, snap-on cover caps and structural thermal break suites, plus accessory sections such as drainage gutter profiles. Because one billet batch and one coating line serve the whole package, colors and mechanical properties stay consistent across every section in the bill of materials.
Q: Can you optimize my mullion cross-section to reduce weight?
A: Yes. Our die engineers review the moment of inertia of your section against the project wind load and deflection limits, then redistribute metal so wall thickness sits where bending stress is highest and non-structural material is reduced. The revised section still meets your structural criteria, but uses less aluminum, which lowers both profile weight and project cost.
Q: Do you offer thermal break curtain wall profiles?
A: Yes. We operate in-house thermal break insertion lines and crimp glass-fiber reinforced polyamide strips into the aluminum section. The mechanical crimp delivers the shear strength the assembly needs while interrupting heat flow between the interior and exterior frame, which helps the facade comply with modern green building codes and condensation requirements.
Q: What fabrication can be done before the profiles ship?
A: Our CNC deep-processing division provides precision fixed-length miter sawing, connector pin milling, drainage slotting and bolt-hole drilling. Shipping pre-machined profiles significantly reduces on-site fabrication errors and field labor cost, and every cut length stays traceable through bundle labels to its billet batch and coating run.
Q: What is the difference between stick and unitized curtain wall profiles?
A: Stick systems are assembled on site from separate mullions and transoms; unitized systems are built as panels in the factory and hung on the structure. Both run as extrusions, but unitized work puts more demand on dimensional repeatability because the panels must fit each other without site adjustment.
Q: Can you extrude a custom mullion section?
A: Yes. Send the section drawing; anything that fits a 540 mm circumscribed circle runs on our presses and you get your own die rather than a catalogue number.
Q: What is the minimum order for curtain wall profiles?
A: 500 kg per section, whether or not a new die is required. Mullions, transoms and covers can be consolidated into one shipment.
Q: How do I specify curtain wall tolerances on a drawing?
A: Name the dimensions that function — mullion depth, groove width, pressure plate screw pitch — and reference GB/T 5237 high-precision class for the rest.
Q: Is ±0.1 mm possible on a curtain wall groove?
A: Yes, on a groove the die is cut for, when the adjacent wall is not a thin isolated tongue. We quote the groove tolerance separately on the drawing.
Q: How long are curtain wall profiles supplied?
A: Mill lengths are 6.0–7.0 m, cut to your list. A 20 ft container takes 5.85 m and a 40 ft takes 6.0 m in two cuts.

=== Curtain Wall Profiles for High-Rise Projects ===
URL: https://www.linkedalu.com/products/architectural-aluminum/curtain-walls/curtain-wall-profiles-high-rise.html
Summary: Custom-extruded curtain wall framing for high-rise towers — one die set, one billet batch, one coating line, documented to GB/T 5237, EN 755-9 or ASTM B221 from the same material.
- Alloy & Temper: 6063-T5
- Profile Type: Curtain wall mullions, transoms, pressure plates, cover caps
- Wall Thickness: 1.2 mm - 6.0 mm
- Tolerance: GB/T 5237 high-precision class
- Surface Finish: Anodizing, PVDF coating
- Length: 6.0 m standard, cut to project length
- Fabrication: Miter sawing, CNC drilling, milling, tapping, drainage slotting
- MOQ: 500 kgs
- Lead Time: Confirmed at order after drawing and die approval
- Standards: GB/T 5237, EN 755-9, ASTM B221
Short answer. Unitized and stick curtain wall profiles for towers: 6063-T6 mullions and transoms up to a 540 mm circumscribed circle, walls 1.2–6.0 mm, mill lengths 6.0–7.0 m, thermally broken on request and machined to your drawing in Foshan. Minimum 500 kg per profile, FOB Shenzhen or Guangzhou. Mullion Depth for Wind Load Above 100 m Unitized and stick curtain wall aluminum profiles in 6063-T6: mullions, transoms, pressure plates and cover caps, thermally broken on request, machined to your interface and cut to your list. Walls run from 1.2 mm to 6.0 mm, mill lengths 6.0 m, 500 kg per profile. Linkedalu Metal Group Co., Ltd extrudes custom curtain wall framing for high-rise projects: vertical mullions, horizontal transoms, exterior pressure plates and cover caps. On a tall building the curtain wall is not an envelope applied to a frame — it moves with that frame, resists the same wind load and has to keep water and air out while it does so. We work from your shop drawings and extrude to the alloy, temper and coating the specification calls out, so the engineer who approves those drawings gets exactly the material that reaches site. One Heat Lot Across GB/T, EN and ASTM High-rise specifications travel. A tower in South America may be written to a national code, while the same facade package is procured against European or American material standards. We run one set of dies, one billet batch and one coating line, then issue mill test certificates against GB/T 5237, EN 755-9 and ASTM B221 from that same material. The result is one documented lot that can be accepted under whichever standard governs the project, without a second extrusion run or a color mismatch between deliveries. Thermal Movement and Interlock Allowance Curtain wall performance is regional. The loads that matter, the code that governs and the corrosion environment all differ, so we tune the section accordingly: Seismic zones. In Chile, where towers are designed to NCh 433, the curtain wall must follow the structural frame through inter-story drift without tearing glass, breaking gaskets or leaking at the joint. That drives the design of the glazing register, the depth of the mullion engagement and the amount of movement the pressure plate allows. Coastal and salt-laden air. Pacific and Gulf coastal sites need coating build and alloy selection chosen for corrosion, not only for color. Hot-humid and high-wind climates. Southeast Asian projects combine typhoon wind pressures with heavy rainfall, so drainage paths, baffles and glazing gasket compression matter as much as section strength. Section Review Before the Die Is Cut Before committing a die, our engineers check the proposed section against your loads. Moment of inertia is compared with wind load and deflection limits, and where the geometry allows we suggest a wall thickness or alloy change that reaches the same performance with less material. Because the review happens at drawing stage, changes cost nothing at site. From Billet to Bundled Profiles: Order Sequence You send shop drawings: cross-sections, fabrication list, surface finish and target standard (GB, EN or ASTM). We verify the section against wind load and deflection limits and confirm the die or propose a revision. Billets are cast and logged, and the order is locked to a single batch. Extrusion, straightening and cut-to-length run together with the coating line for the same project. CNC machining follows: miter sawing, drainage slotting, bolt-hole drilling, tapping and milling. Profiles are labeled and packed in sequence, with mill test certificates and packing lists issued against bundle labels. Heat Number Traceability for Facade Audits Packing lists are tied to your bundle labels, so every cut length can be traced back to the billet batch and the coating run it came from. If a question arises on site about a specific frame member, the material history is retrievable rather than reconstructed. 6063-T6 and AA15 for Coastal Towers 6063-T5 is the standard alloy for this product family: it extrudes cleanly across deep multi-cavity mullion sections and anodizes evenly. Anodizing and PVDF are the usual finishes for high-rise facades, chosen by exposure — anodizing where a metallic appearance and abrasion resistance are wanted, PVDF where color stability and gloss retention matter over decades of sunlight and salt spray. Both are applied over the same verified alloy and temper so the certificate and the appearance correspond.
Q: Can one material lot be certified to GB, EN and ASTM standards?
A: Yes. We run one set of dies, one billet batch and one coating line, then issue mill test certificates against GB/T 5237, EN 755-9 and ASTM B221 from that same material. This means the engineer approving your shop drawings receives exactly the alloy, temper and coating specified, whichever material standard the project is written to.
Q: How do you handle seismic movement in a high-rise curtain wall?
A: In seismic regions such as Chile, where towers are designed to NCh 433, the curtain wall must follow the structural frame through inter-story drift without tearing glass or leaking. We address this in the section geometry: the glazing register, the depth of mullion engagement and the movement allowance built into the pressure plate and gasket compression.
Q: What information do you need to quote a high-rise facade package?
A: Send shop drawings with cross-sections, your fabrication list, the required surface finish and the target standard — GB, EN or ASTM. With those we can verify each section against your wind load and deflection limits, confirm the die or propose a wall-thickness or alloy change, and quote the complete bill of materials.
Q: Is machining available before the profiles are packed?
A: Yes. CNC deep processing covers precision miter sawing to fixed length, connector pin milling, drainage slotting, bolt-hole drilling and tapping. Delivering pre-machined profiles limits on-site fabrication error and field labor cost, and each cut length stays traceable to its bundle label, billet batch and coating run.
Q: What changes in the extrusion for a high-rise facade?
A: Section depth and wall thickness rise with wind load, and the system has to absorb movement rather than resist it. That usually means 6061-T6 instead of 6063-T5 where the mullion is the load path.
Q: Do you supply profiles for seismic zones?
A: We extrude the sections and machine them to your drawings. The movement joints and the structural design behind them are specified by the facade engineer; we make the extrusion that carries the detail.
Q: What is the minimum order?
A: 500 kg per section. A tower package with several mullion and transom dies consolidates into one or more shipments.
Q: What changes in a curtain wall profile above 100 m?
A: Mullion depth and wall thickness rise with wind load, and interlock clearance has to absorb more thermal and structural movement, so the section is reviewed before the die is cut.
Q: Can you supply unitized panels or only profiles?
A: We extrude, thermally break and machine the profiles and cut them to length. Panel assembly and glazing stay with the facade contractor.
Q: How do you keep one heat lot across a tower order?
A: Billets for a project are booked as one lot and extruded in sequence, with heat numbers recorded against every bundle.

=== Louver and Sunshade Extrusion Profiles ===
URL: https://www.linkedalu.com/products/architectural-aluminum/louver/louver-sunshade-extrusion-profiles.html
Summary: Custom-extruded aluminum louver blades and complete louver systems — Z-blade, airfoil and C-blade profiles with mullions, drive linkage channels, pressure plates and sill drainage sections.
- Alloy & Temper: 6063-T5 / 6063-T6 / 6005A-T6
- Profile Type: Z-blade, airfoil, C-blade and custom louver cross-sections
- Wall Thickness: 1.2 mm - 6.0 mm
- Tolerance: GB/T 5237 high-precision / ±0.15 mm on drive linkage slots
- Surface Finish: Polyester powder coating (full RAL range), anodizing, PVDF
- Length: 6.0 m standard, cut to project length
- Fabrication: CNC drilling and milling, cut-to-length, notch and slot machining, label to call-up list
- MOQ: 500 kgs
- Lead Time: Confirmed after die and sample approval
- Standards: GB/T 5237, EN 755-9, ASTM B221
Louver Profiles Built From Your Drawings Louver and sunshade profiles — Z-blade, airfoil, C-blade and custom sections — are extruded in 6063-T5/T6 or 6005A-T6 with 1.2–6.0 mm walls and supplied in 6.0 m mill lengths, cut and machined to your call-up list. 500 kg per profile. At Linkedalu Metal Group Co., Ltd we manufacture custom aluminum louver profiles engineered specifically for architectural sunshade systems, commercial facade ventilation and heavy-duty industrial screening. We do not force a design into the limitations of a standard catalog. Every blade, frame and mullion is custom-extruded from your architectural drawings: your project sets the cross-section, the structural requirement and the finish specification, and our Foshan-based facility builds the precision die to match. From concept blueprint to coordinated on-site delivery, one supplier carries the whole system. Alloy Selection for Louver Blades For most architectural louver projects, 6063-T5 is the right starting point. It extrudes cleanly, anodizes evenly and provides adequate strength for typical blade spans. We step up to T6 or recommend 6061 only when span, wind load calculation or local building code specifically requires the higher strength. Choosing alloy against the actual blade span and fixing condition keeps weight and cost proportionate to the load the blade really carries. Blade Geometries Z-blade — a fixed sightline-controlled profile for standard facade screening, giving good light control in a simple section. Airfoil blade — a streamlined section that moves air cleanly, used where appearance and air path both matter. C-blade — a shaped channel section suited to sunshade arrays where blade depth and stiffness are driven by span. Each geometry is defined by the die to your drawing, not selected from a fixed range, so blade depth, nose radius and fixing flange are set by your solar and structural criteria. Complete System Extrusion A louver array is a system, so we extrude and supply the surrounding components as one matched package: System component Function Key specification Blades Primary shading and ventilation element Custom cross-section to your design Mullions Intermediate vertical supports Required when blade span exceeds the structural limit Drive linkage channels Housing for motorised adjustment mechanisms ±0.15 mm slot tolerance for smooth operation Pressure plates and cover caps Blade retention and aesthetic finishing Snap-fit or screw-fixed, profile-matched to frame Sill drainage profiles Water management at the base of the louver Integrated drainage slots and sloped design Surface Finishes and Environmental Suitability Polyester powder coating applies a durable organic resin layer that fully encapsulates the aluminum. It offers the widest color range, full RAL palette, with good UV and corrosion resistance at a competitive cost — the workhorse finish for most commercial facade louvers. Anodizing is used where a metallic appearance and abrasion resistance are wanted, and PVDF is specified for severe UV and coastal exposure at higher build thickness. The finish is matched to the site exposure rather than applied uniformly. Drive Systems and Operable Louvers For operable louver systems, the drive linkage channel is the component that decides whether the array moves smoothly for the life of the building. If you have a specific drive system in mind, share the manufacturer's specifications during die design and we integrate the required slot geometry directly into the blade cross-section, holding the slot to a tolerance that keeps the linkage running without binding. Quality Documentation and Packing Profiles are extruded, straightened, cut to length, CNC machined and finished as one sequence, then labeled to your installer's call-up list and packed so each blade can be traced to its bundle, coating run and mill test certificate. Material is documented to GB/T 5237, EN 755-9 or ASTM B221 from the same press run, with measured mechanical properties and coating parameters recorded. From Drawing to Die to Packing Working from your architectural drawings, our team confirms the blade section, then cuts a new die or reuses an existing one for the run. The order is locked to a single billet batch, so the blades that arrive at the end of the project have the same mechanical properties and the same color as the first delivery. Extrusion is followed by straightening, cut-to-length and CNC machining, then the finish, then labeling and sequence packing to your installer's call-up list. Mill test certificates travel with the shipment, and each bundle label ties back to the billet batch and coating run. If a site query arises about a particular blade, the material history is retrievable rather than reconstructed from memory.
Q: Which alloy should I choose for louver blades?
A: For most architectural louver projects 6063-T5 is the right starting point: it extrudes cleanly, anodizes evenly and carries adequate strength for typical blade spans. We only recommend stepping up to T6 or 6061 when blade span, wind load calculation or local building code specifically requires the additional strength.
Q: Can the blades be made to my own cross-section?
A: Yes. Every blade is custom-extruded from your architectural drawings rather than pulled from a catalog. Your project dictates the cross-section, structural requirements and finish specification, and we build the precision die to match that geometry, including the fixing flange, blade depth and nose radius your design calls for.
Q: Do you support motorised operable louver systems?
A: We extrude the drive linkage channels that house motorised adjustment mechanisms, holding slot tolerance to about ±0.15 mm so the linkage runs without binding. If you have a specific drive system in mind, share the manufacturer's specifications during die design and we integrate the required slot geometry into the blade cross-section.
Q: How are louver profiles packed and identified?
A: Profiles are extruded, straightened, cut to length, CNC machined and finished, then labeled and packed in sequence to your installer's call-up list. Each blade is traceable to its bundle, coating run and mill test certificate, and material is documented to GB/T 5237, EN 755-9 or ASTM B221 from the same press run.
Q: Fixed or operable sunshades — which do you supply?
A: Both blade types are extruded here. The difference is whether the blade carries an axle detail for rotation or a fixed end plate.
Q: What blade shapes can you extrude?
A: Flat, angled, elliptical and airfoil blades are all run as extrusions. Send the blade section; the limit is the 540 mm circumscribed circle, not the shape.
Q: What is the minimum order?
A: 500 kg per section, whether or not a new die is required.

=== Operable Louver Profiles for Facades and Car Parks ===
URL: https://www.linkedalu.com/products/architectural-aluminum/louver/operable-louver-facade-profiles.html
Summary: Engineered aluminum louver profiles for facades, sunshades, parking structures and operable systems — sections designed to your solar, wind and visual-comfort criteria, not a catalog default.
- Alloy & Temper: 6063-T5 / 6063-T6 / 6061-T6
- Profile Type: Fixed sunshade blades, parking structure screens, operable louver sections
- Wall Thickness: 1.2 mm - 6.0 mm
- Tolerance: GB/T 5237 high-precision class
- Surface Finish: Polyester powder coating, PVDF at AAMA 2605 specification for coastal sites (>=30 um over primer)
- Length: 6.0 m standard, cut to project length
- Fabrication: Cut-to-length, CNC drilling and milling, linkage slot machining, sequence packing
- MOQ: 500 kgs
- Lead Time: Confirmed after die and sample approval
- Standards: GB/T 5237, EN 755-9, ASTM B221
A Louver Is a Thermal-Control System, Not a Trim Piece Operable louver sections and fixed sunshade blades are extruded in 6063-T5/T6 or 6061-T6 with 1.2–6.0 mm walls, with linkage slots machined after extrusion so the blades line up across the run. 6.0 m mill lengths, 500 kg per profile. A louver on a high-rise is often treated as a finish detail, a decorative band that makes a facade look better in a rendering. It is not. On a glazed office tower, a correctly engineered fixed sunshade array reduces cooling load by roughly 8 to 15 percent. On a west-facing school it can move afternoon glare from unworkable to comfortable. On a parking structure it can conceal the majority of the cars from the street view while still admitting useful daylight. Linkedalu Metal Group Co., Ltd extrudes custom aluminum louver profiles for exactly these duties — fixed sunshades, operable systems, parking structure screens and architectural feature blades — engineered to your solar, wind and visual-comfort criteria rather than a catalog default. What a Louver Does to a Building's Energy Load Most glazing specifications are written for visible light transmission and U-value. They do not account for solar heat gain through a glass envelope at two in the afternoon in August. A shading system does, and it works on the geometry of the blade rather than on the glazing itself: blade depth, pitch, tilt and projection together decide how much direct sun is intercepted and how much diffuse daylight still reaches the interior. Because the section is extruded to your drawing, that geometry is set by calculation, not by the nearest available catalog blade. Louver Applications and What Each Demands Facade sunshades. Long, straight blade runs where stiffness across the span and a clean sightline both matter. Parking structure screens. High-coverage arrays that hide vehicles from the street while maintaining ventilation and daylight, which puts the emphasis on blade pitch and open area. Operable systems. Blades that rotate on the drive linkage, so slot geometry and tolerance decide how smoothly the array moves over decades of use. Ventilation and plant screening. Sections used where airflow and visual screening outweigh shading performance. Engineering, Extrusion and Machining Sequence Each order follows one route. A new die is cut or an existing die is reused, and the run is locked to a single billet batch so the mechanical properties and color stay uniform. Extrusion runs through straightening and cut-to-length, then CNC drilling and milling, then the finish, then labeling. The mill test certificate is issued to GB/T 5237, EN 755-9 or ASTM B221 with measured mechanical properties and coating parameters. Finally the profiles are packed and sequenced to your installer's call-up list. On the integration side we provide bracket geometry that does not break the curtain wall's drainage or sealant plane. Finishes by Climate Finish selection is driven by exposure. For a typhoon-zone coastal site such as Manila, Ho Chi Minh City or Jakarta, PVDF at AAMA 2605 specification and at least 30 um over primer holds color and gloss under salt spray and UV better than standard polyester powder. Inland projects with moderate exposure are usually well served by a super-durable polyester powder, and interior or sheltered louver screens can use a lighter architectural coat. Alloy Choice for Blade Span 6063-T5 is the standard alloy for architectural louver extrusion: it forms clean blade sections, anodizes and coats evenly, and carries typical facade spans. It is not the only option. Where blade span, wind pressure or local code demand higher strength, T6 or 6061 is used, and the choice is confirmed against your structural criteria before the die is cut. Sequence Packing and Site Coordination Louvers arrive in the order the installer will fit them. Profiles are packed in sequence to the call-up list, with bundle labels traced to the billet batch and the coating run behind them, so a crew can work elevation by elevation instead of sorting mixed bundles on the scaffold. For facade-mounted arrays, the bracket geometry we supply is designed not to break the curtain wall's drainage path or its sealant plane, which is the point where shading systems most often cause leaks when they are added to an existing envelope. Operable arrays are packed by zone so that blades, linkage channels and drive components for one section arrive together.
Q: How much can a facade louver system reduce cooling load?
A: On a glazed office tower a correctly engineered fixed sunshade array can cut cooling load by roughly 8 to 15 percent, because it intercepts direct solar gain before it reaches the glass. The exact figure depends on orientation, glazing specification, blade depth, pitch and tilt, so the array is engineered against your solar and load criteria rather than specified from a catalog.
Q: Which alloy do you use for long louver blade runs?
A: 6063-T5 is the standard starting point: it extrudes cleanly, coats evenly and gives adequate strength for typical blade spans. Where span, wind load calculation or local building code requires higher strength, we move to T6 or 6061. The alloy is confirmed against your structural criteria before the die is cut.
Q: What finish do you recommend for a louver in a hot-humid climate?
A: For a typhoon-zone coastal site, PVDF at AAMA 2605 specification and at least 30 um over primer holds color and gloss under salt spray and UV better than standard polyester powder. Inland sites with moderate exposure are usually served well by a super-durable polyester powder at comparable build thickness.
Q: Can louvers be delivered as part of an operable system?
A: Yes. Operable louver arrays rotate on a drive linkage, so the blade section includes a linkage slot machined to a tight tolerance to keep movement smooth. We also supply bracket geometry designed not to break the curtain wall's drainage or sealant plane, and profiles are packed in sequence to your installer's call-up list.
Q: What makes a louver operable rather than fixed?
A: The blade carries an axle detail and the frame carries the bearing, so the blade rotates instead of being locked in place. Both details live in the extrusion, which is why an operable system needs its own die.
Q: Do you supply the linkage as well?
A: We extrude and machine the blade and frame sections. The linkage and actuator are normally specified by the facade contractor; we machine the mounting detail to their drawing.
Q: What is the minimum order?
A: 500 kg per section, whether or not a new die is required.

=== Glass Railing and Balustrade Profiles ===
URL: https://www.linkedalu.com/products/architectural-aluminum/guardrail/glass-railing-balustrade-profiles.html
Summary: Custom extruded aluminum glass railing profiles — handrails, posts, glass shoe sections, toe plates and base trims for balcony and stair balustrades, in 6063-T6 or 6061-T6.
- Alloy & Temper: 6063-T6 / 6061-T6 / 6005A-T6
- Profile Type: Handrails, posts, glass shoe sections, toe plates, cover caps
- Wall Thickness: 1.2 mm - 6.0 mm
- Tolerance: GB/T 5237 high-precision class
- Surface Finish: Anodizing AA10 or above; super-durable polyester powder 60-80 um; PVDF 3-coat approx. 35 um for coastal
- Length: 6.0 m standard, cut to project length
- Fabrication: Cut to finish length, drainage hole drilling, tapping, notching, label to drawing
- MOQ: 500 kgs
- Lead Time: Confirmed after die and sample approval
- Standards: GB/T 5237, EN 755-9, ASTM B221
Aluminum Glass Railing Systems, Extruded to Your Drawing Glass railing and balustrade profiles — handrails, posts, glass shoe sections and toe plates — are extruded in 6063-T6, 6061-T6 or 6005A-T6 with walls from 1.2 mm to 6.0 mm, then drilled, tapped and notched to your drawing. 500 kg per profile; anodized AA10 or powder coated 60–80 µm. Linkedalu Metal Group Co., Ltd extrudes aluminum glass railing profiles for balcony and stair balustrades: handrails, posts, glass shoe sections, toe plates and base trims. A glass balustrade is a structural assembly, not a decorative edge. The base shoe has to carry the wind and line load the glass imposes, and the handrail has to do that while staying straight, dimensionally stable and visually consistent across the whole elevation. We build the sections from your drawings, so the profile geometry, glass pocket width and fixing details match the system you have designed rather than a generic stock section. Component Set The railing system is supplied as a matched component family, extruded in one project lot: Handrails — round, rectangular or shaped sections, continuous over the run. Posts — supporting members in surface-mounted, base-plate and cantilevered configurations. Glass shoe sections — the base profile that holds the laminated glass, with a controlled pocket and gasket register. Toe plates and base trims — closure and finish for the shoe at floor level. Cover caps and end caps — profile-matched closure for the visible ends of the run. Three Problems Installers Raise, and How the Profile Answers Them After a couple of years, some balustrades show white streaks staining the surface below the railing, with the coating looking dull. The cause is almost always a finish chosen without reference to the actual exposure, so we match finish to site: for inland residential with partial shade, a super-durable polyester powder at 60 to 80 um is appropriate; for full sun with no shade, PVDF three-coat; for coastal or poolside, PVDF without exception. The second recurring problem is glass pocket tolerance: if the shoe pocket and gasket register are not held tightly, the glass rattles or the gasket extrudes. The third is inconsistent anodizing or coating color between deliveries on a phased project. Aluminum Alloy and Finish by Environment Finish selection is a service-life decision, and we recommend it against the environment the balustrade will actually see: Environment Finish Specification note Interior, dry Anodized AA10 or light powder coat Standard architectural finish Outdoor full sun, inland PVDF 3-coat or super-durable powder PVDF preferred for color stability Coastal under 1 km PVDF 3-coat Approx. 35 um and above, 20+ year service life How We Ship Railing profiles are delivered in whichever state your installation sequence needs. Some fabricators take raw extrusions, straightened and cut to rough length, and complete all fabrication themselves. Others take pre-machined blanks, cut to finish length with drainage holes drilled, leaving final assembly drilling and tapping on site. For the fastest installation we supply the full kit: every bar cut, drilled, tapped, notched and labeled to your drawing, packed by assembly zone so the crew opens one bundle per balcony. Material and Documentation 6063-T6 is the standard alloy for this product family, giving a good balance of extrudability and strength for handrail and shoe sections; 6061-T6 is used where a component is heavily loaded. Profiles are documented to GB/T 5237, EN 755-9 or ASTM B221 as the project requires, with mill test certificates issued for each lot. Why Profile Tolerance Matters in a Glass Balustrade A balustrade is judged by its sightline: one post set a few millimeters low, or a handrail that steps at a joint, is visible from across the street. Section tolerance is what keeps that sightline true, which is why railing profiles are extruded to the high-precision class rather than general commercial tolerance. The same discipline applies to the glass pocket in the base shoe, where the gasket register has to hold the laminated panel at the designed depth without letting the gasket extrude or the glass rattle under wind load. Fabrication, Packing and Traceability Profiles are straightened, cut and machined, then labeled and packed by assembly zone so each balcony or stair flight receives its own bundle. Mill test certificates covering alloy, temper and coating are issued with each lot, and material is documented to GB/T 5237, EN 755-9 or ASTM B221 as the project requires.
Q: Which finish should I specify for a balcony railing?
A: It depends on exposure. Inland residential with partial shade is well served by a super-durable polyester powder at 60 to 80 um, which we rate for around 15 years. Full sun with no shade calls for PVDF three-coat. Coastal or poolside locations, within roughly 1 km of salt water, should use PVDF three-coat at about 35 um or more for a 20-year plus service life.
Q: Do you supply glass shoe sections for frameless balustrades?
A: Yes. The base shoe is one of the cores of this product family, extruded with a controlled glass pocket and gasket register so the laminated glass sits at the designed depth. Toe plates, base trims and cover caps are extruded in the same lot, so the visible finish matches across the whole assembly.
Q: Can you deliver railing profiles already cut, drilled and tapped?
A: Yes, in three levels. Raw extrusions are straightened and cut to rough length for fabricators who do all the machining. Pre-machined blanks are cut to finish length with drainage holes drilled. A full kit arrives with every bar cut, drilled, tapped, notched and labeled to your drawing, packed by assembly zone so each balcony has its own bundle.
Q: What alloy is used for aluminum handrail and post profiles?
A: 6063-T6 is the standard alloy for this family. It extrudes cleanly into handrail and shoe sections and gives a good balance of strength and finish quality. Where a post or a bracket component carries heavy load, 6061-T6 or 6005A-T6 is used instead. Profiles are documented to GB/T 5237, EN 755-9 or ASTM B221 as the project requires.
Q: Which glass thicknesses does the base shoe take?
A: The channel is machined to the glass and the clamping detail you specify rather than to a fixed stock size. Send the glass thickness and the wind load.
Q: Do you machine the clamp detail?
A: Yes. The shoe, the clamp and the gasket groove are machined after extrusion, so the glass sits at the line the facade drawing sets.
Q: What is the minimum order?
A: 500 kg per section, whether or not a new die is required.

=== Sunroom and Screen Room Frame Extrusions ===
URL: https://www.linkedalu.com/products/architectural-aluminum/sunrooms/sunroom-screen-room-extrusions.html
Summary: Full-frame aluminum extrusions for sunrooms, screenrooms and verandas - main beams, rafters, columns, integrated gutters and glazing beads produced to your drawing, with thermal break and single-batch finishing.
- Alloy & Temper: 6063-T5 for trims and beads / 6063-T6 for load-bearing beams, columns and rafters
- Webster Hardness: 10 ±2 HW
- Profile Range: Ridge and cross beams, rafters, front and rear columns, integrated gutter, glazing beads, base tracks, connector stock
- Wall Thickness: 1.5 mm - 5.0 mm, sized to span and load
- Tolerance: GB/T 5237 high precision; glazing bead clipping leg ±0.15 mm
- Surface Finish: Powder coating (standard), PVDF, anodizing - single-batch finishing for color match across the set
- Thermal Break: Polyamide barrier with crimped bridge for heated and mixed-climate enclosures
- Standard Length: 6.0 m
- Fabrication: Precision cutting, punching, tapping, milling, pre-machined drainage outlets
- MOQ: 500 kg per profile
Custom Extruded Profiles for Sunrooms, Screenrooms, Conservatories and Verandas We extrude the aluminum sections that hold a glazed enclosure together: main beams, columns, rafters, integrated gutters, glazing beads, base tracks and connector stock. Every profile we produce starts as your drawing, whether that means a complete system with thirty unique sections or a single beam you have been unable to source. We do not keep a catalog of stock shapes, because the cross-section that suits a compact patio enclosure in a mild climate is rarely the one that will carry a five-meter glazed roof holding 120 kg/m² of snow. Instead, the die is built around your span, your glass weight and your local building code. What we bring is direct experience of the parts that cause trouble on site: beams that deflect more than they should, gutters that overflow at the outlet, thermal breaks that separate after a few seasons, and frames where the rafters arrive in a visibly different shade from the columns. A Sunroom Is a System, Not a Pile of Bars Rectangular tube bought off the shelf can be bolted into something that looks like a veranda. A proper enclosure uses purpose-designed extrusions, each of which performs one job well. We extrude the full set so that the sections fit each other and match in finish. Main beams: ridge and cross beams These carry the roof. The cross-section has to resist bending under glass and snow load, so the moment of inertia is sized to your span rather than guessed. Web depth, flange width and wall thickness all move together to reach the required stiffness without adding dead weight to the columns below. Rafters and sloped roof bars Rafters support the glass directly. Their top face carries a flat glazing platform and a groove for the bead, and where a shade track is required it can be extruded into the underside of the die rather than added as a separate part. Rafter spacing and the glazing platform width are set from your glass thickness and fixing detail. Front and rear columns Rear columns usually sit against a wall, so a half-profile is often the right answer and saves both weight and cost. Front columns are freestanding and take the full roof load plus wind pressure. Both can be produced within the same system so the visual language of the frame stays consistent around the enclosure. Integrated gutter and drainage The lowest rafter or a dedicated gutter section catches the runoff. We extrude the correct fall into the profile and form a drip nose so water does not track back along the soffit to the wall. Drainage outlets are pre-machined to your positions, which removes a wet-trade operation from the installation sequence. Glazing beads, base tracks and connectors Snap-in or screw-fixed beads hold the glass in the rafter and column grooves. The clipping leg is held to ±0.15 mm, because a loose bead lets the glass rattle and an oversized one makes the installer's day miserable. Base tracks anchor the frame to deck or concrete, and connector stock lets you join sections cleanly where a single length will not reach. Alloy, Thermal Break and Finish Structural sections are extruded in 6063-T6 for the higher yield strength that spans and snow loads demand, while non-structural trims and beads are produced in 6063-T5. Where the enclosure is heated or the climate swings between seasons, a polyamide thermal barrier with a crimped bridge interrupts the path between the inner and outer faces and reduces condensation on the frame. Powder coating is our standard finish. PVDF and anodizing are available where the project calls for them. The point that matters most on a sunroom is color consistency across the set: rafters, columns, gutter and beads are finished as one batch so that no part of the frame reads as a different color in daylight. Tolerance, Fabrication and Delivery Profiles are supplied to GB/T 5237 high-precision tolerances, with critical glazing and assembly dimensions controlled at the die rather than corrected afterwards. Standard length is 6.0 meters, and cutting, punching, tapping, milling and outlet machining can all be carried out before shipment. Packaging is shrink film for protection in transit. Minimum order quantity is 500 kg per profile, which lets a small system of a few sections travel in the same container as a full set. What to Send for a Quotation Cross-section drawings and the required alloy and temper for each section Roof span, rafter spacing and the design snow and wind loads Glass build-up and thickness so the glazing platform and bead groove are sized correctly Finish type, color reference and whether the section is exposed to coastal air Quantity per section, plus any cutting, punching or outlet machining required Send the drawing set and we will review manufacturability, flag any section that will not extrude cleanly, and quote from there.
Q: Can you extrude a complete sunroom system rather than individual bars?
A: Yes. A full frame set is our normal way of working: main beams, rafters, front and rear columns, integrated gutter, glazing beads, base tracks and connector stock are all extruded from your drawings as one package. Because the sections are designed and finished together, they fit each other and match in color, and the whole set ships in one batch instead of arriving from several suppliers with slightly different shades and tolerances.
Q: How do you decide the cross-section for a given roof span?
A: The die is sized around your span, glass weight and local building code rather than chosen from a fixed catalog. We work from the required moment of inertia, then set web depth, flange width and wall thickness to reach the stiffness the roof needs while keeping dead load off the columns. Rafter spacing, glazing platform width and bead groove follow from your glass thickness and fixing detail.
Q: Do you supply thermal break sections for sunrooms and verandas?
A: Yes. Where an enclosure is heated, or where the local climate swings strongly between seasons, we produce profiles with a polyamide thermal barrier and a crimped bridge. The barrier interrupts the conductive path between the inner and outer faces of the frame, which reduces heat loss and keeps the inner surface above the dew point so condensation does not run down the frame in winter.
Q: What information do you need to quote a custom sunroom profile?
A: Send cross-section drawings, the alloy and temper required for each section, roof span and rafter spacing, design snow and wind loads, and the glass build-up. Tell us the finish type and color reference, whether the frame is exposed to coastal air, the quantity per section and any cutting, punching or drainage outlet machining. From that set we review manufacturability and quote.
Q: Can you match the section on an existing sunroom?
A: Send a cut sample or the section drawing. If the original die still exists we can run it; if not, we measure the section and cut a new die to match the fit.
Q: Do you supply cut-to-size kits?
A: Yes. Cut to your opening size, with the mitre and fixing details machined, so the room assembles without a saw on site.
Q: What is the minimum order?
A: 500 kg per section, whether or not a new die is required.

=== Anodized Window and Door Frame Profiles ===
URL: https://www.linkedalu.com/products/architectural-aluminum/windows-doors/anodized-window-door-frame-profiles.html
Summary: 6063-T5 window and door frame profiles finished on our in-house anodizing line, with controlled 10 ±2 µm film thickness, four standard colors and GB/T 5237 precision tolerances.
- Alloy Grade: 6063-T5 architectural grade
- Surface Treatment: Anodizing - silver, champagne, bronze, black
- Webster Hardness: 10 ±2 HW
- Anodic Film Thickness: Standard 10 ±2 µm; thickened to 15, 20 or 25 µm on request
- Salt Spray Resistance: ≥500 hours at 10 µm; 1000+ hours with thickened films
- Tolerance Standard: GB/T 5237 high precision / super high precision
- Applications: Casement window frames, sliding tracks, premium door frames
- Standard Length: 6.0 m
- MOQ: 500 kg per profile
- Lead Time: 10-15 working days for tooling; 20-25 days for total sampling
Anodized Aluminum Window and Door Frame Profiles in 6063-T5 Anodized aluminum profiles in AA10 or AA15 — window and door sections, trims and custom shapes — in silver, champagne, bronze, black and gold, cut to your list from 500 kg per profile. Other colours are quoted on request. Anodizing is not a coating applied on top of the metal. It is an electrochemical conversion of the aluminum surface itself. The profile is made the anode in an acid electrolyte, and a dense oxide layer grows out of the substrate and into it, so there is no interface where a film can lift or peel. That is why anodized aluminum window and door frames keep their appearance in coastal air, in polluted city centers and on buildings that are washed rarely, if ever. We run an in-house anodizing line, which means the film thickness, the color and the surface texture are controlled under one roof instead of being subcontracted. For window and door brands, that matters for a simple reason: the frame is the part of the window the customer sees every day, and a color that drifts between production runs is a complaint waiting to happen. Film Thickness Control: 10 ±2 µm as Standard Our standard anodic film is 10 ±2 µm, and running our own line lets us hold that band tightly rather than averaging out of a wide range. For more demanding exposure, the layer can be built up to 15, 20 or 25 µm on request. The difference is not cosmetic. A thicker oxide layer takes proportionally longer to break down under salt and humidity, which is why a thickened film is the normal specification for facades within a few hundred meters of the sea. Corrosion performance tracks that thickness. Standard 10 µm profiles are tested to at least 500 hours of neutral salt spray, and thickened films extend that beyond 1000 hours. The exact figure that applies to your order is stated on the inspection report for the batch that ships. Strength and Workability: Webster Hardness 10 ±2 HW Window and door frames are fabricated, not just installed. Profiles are sawn to length, punched for hardware, crimped at the corners and screwed through. A frame that is too soft deforms under the crimping die and will not hold a miter closed; one that is too hard cracks at the corner or dulls tooling faster than the fabricator can tolerate. Holding Webster hardness at 10 ±2 HW keeps the profile rigid enough to carry heavy glazing and ductile enough to survive high-speed punching and corner crimping without cracking. Colors and Textures Anodizing produces its color through the oxide layer rather than through pigment, and the range covers silver, champagne, bronze and black. Because the finish is integral to the metal, it keeps a metallic depth that paint and powder cannot reproduce, and the surface stays conductive and weldable in the areas left unsealed. Color consistency between profiles in the same order is controlled by processing the frame set together, so a casement outer frame, its sash and the matching door threshold read as one material. Tolerances and Fabrication Profiles are produced to GB/T 5237 high-precision and super high-precision tolerances, with critical assembly dimensions controlled at the die. Casement window frames, sliding tracks and premium door frames all depend on the same thing: a consistent section so that hardware, gaskets and beads fit without hand-fitting on the assembly line. Cutting, punching, tapping and milling can be carried out before shipment if you would rather receive ready-to-assemble parts. Lead Time, Packing and Ordering Tooling takes around 10 to 15 working days, with total sampling at 20 to 25 days. Profiles are supplied in standard 6.0 meter lengths, protected in shrink film, and minimum order quantity is 500 kg per profile. Delivery can be arranged FOB or CIF depending on how your logistics are set up. Send your drawings, the color reference and the exposure class of the building, and we will confirm the film thickness and finish that suits the project.
Q: Why choose anodized aluminum for window and door frames?
A: Anodizing converts the aluminum surface into a dense oxide layer that is integral to the metal, so there is no film to lift, blister or peel. The result resists wear, scratching and atmospheric corrosion, which matters most in coastal and humid regions. It also gives a metallic depth of color that powder coating cannot match, and it stays stable under UV without chalking or fading in the way an organic coating can.
Q: What film thickness should I specify for a coastal project?
A: Our standard film is 10 ±2 µm, tested to at least 500 hours of neutral salt spray, and that is sufficient for many inland and urban facades. For buildings close to the sea, or anywhere with high humidity and airborne chloride, we build the layer up to 15, 20 or 25 µm, which extends salt spray performance beyond 1000 hours and lengthens the service life of the frame considerably.
Q: How does the 10 ±2 HW hardness affect fabrication?
A: Webster hardness at 10 ±2 HW is the balance point between strength and workability. The profile is rigid enough to support heavy glass loads and resist deflection, while remaining ductile enough to be sawn, punched and corner-crimped at production speed without cracking or distorting. Profiles outside that band tend to cause miter joints that open up or tooling that wears prematurely on the assembly line.
Q: How long does an anodized profile order take?
A: Tooling takes approximately 10 to 15 working days, and total sampling runs to about 20 to 25 working days once the die is cut and the first anodized lengths are produced. Production quantities follow after sample approval. Profiles are supplied in standard 6.0 meter lengths, packed in shrink film, with a minimum order quantity of 500 kg per profile and FOB or CIF delivery terms available.
Q: Which anodizing thicknesses do you offer?
A: AA10 and AA15 are the standard range for window and door work. AA20 is rarely specified and rarely produced.
Q: Does the anodized finish match between orders?
A: Within a batch, yes, because the profiles are anodized together. Across batches we hold a master sample and check against it before packing.
Q: What is the minimum order for anodized window profiles?
A: 500 kg per section, whether or not a new die is required.

=== Powder Coated Window and Door Frame Profiles ===
URL: https://www.linkedalu.com/products/architectural-aluminum/windows-doors/powder-coated-window-door-frame-profiles.html
Summary: 6063-T5 window and door frame profiles, extruded to your drawings and powder coated in-house with RAL color matching, tight assembly tolerances and full OEM/ODM die development.
- Alloy Grade: 6063-T5 architectural grade
- Hardness: 10 ±2 HW (Webster)
- Surface Treatment: Powder coating with RAL color matching; textured and metallic finishes available
- Coating Thickness: 60-80 µm standard, customizable on request
- Tolerance Standard: GB/T 5237 high precision; critical assembly dimensions within ±0.2 mm
- Applications: Casement windows, sliding doors, partition frames, glazing beads, sub-frames and coupling profiles
- Deep Processing: Precision cutting, punching, tapping and milling
- Standard Length: 5.8 - 6.0 m
- MOQ: 500 kg per profile
- Lead Time: 10-15 days for die and mold; 15-20 days for production
Powder Coated Aluminum Window and Door Frame Profiles From blueprint to finished frame, we produce 6063-T5 architectural profiles by hot extrusion and finish them with powder coating on our own line. The profiles are made for window and door brands that need a frame to arrive already finished: outer frames, sashes, mullions, transoms, thermal break sections, glazing beads and sub-frames, all extruded to drawing and coated to the color you specify. More than twenty years in aluminum extrusion has taught us where the problems hide. A section that looks right on a drawing can be impossible to crimp at the corner, or too thin at the screw boss so the fixing strips out. Our engineering team reviews every die design before it is cut so those issues are settled on paper rather than on your assembly line. Optimized Mechanical Performance Webster hardness is held at 10 ±2 HW. That band gives frames the rigidity to carry heavy glazing without visible deflection under wind load, while keeping the alloy ductile enough to prevent cracking during high-speed punching and corner crimping. Thermal break profiles are produced with a polyamide barrier so the frame separates the warm inner face from the cold outer face, which reduces heat loss and keeps condensation off the interior surface. Weatherproof Coating and Color Control Powder coating is applied electrostatically and cured in an oven, producing a continuous film that blocks moisture and oxygen from reaching the aluminum. We use established powder brands such as AkzoNobel and Tiger. Adhesion is rated Grade 0, salt spray testing runs to at least 1000 hours without corrosion, and the coating is formulated for more than ten years of color retention without chalking under UV exposure. Coating thickness is normally 60 to 80 µm and can be adjusted on request for a heavier build or a specific specification. RAL color matching is available, with textured and metallic finishes offered alongside the standard range. Because the profiles in an order are pretreated, sprayed and cured together, the outer frame, sashes and trims arrive as one consistent color rather than as three close-but-not-identical tones. Tight Tolerances on Assembly Dimensions Critical assembly dimensions are controlled within ±0.2 mm and the profiles are produced to GB/T 5237 high-precision tolerances. The purpose of that discipline is straightforward. Gaps between frame and sash are where drafts and noise enter, and where drained-and-ventilated systems fail if the drainage path does not line up. Holding the mating dimensions close eliminates rattle after assembly and helps the finished window meet its energy efficiency and sound insulation targets without shimming on site. OEM and ODM Development We accept DWG, STEP and PDF files for new profile development. Every mold design is reviewed for manufacturability before cutting, which reduces the risk of a design-to-production discrepancy appearing after the die is already made. Deep processing is available alongside extrusion: precision cutting, punching, tapping and milling, so you can receive parts that go straight to assembly rather than lengths that still need several operations. Traceable Quality and Lead Time Traceability runs from raw aluminum ingot spectral analysis through to final film thickness and color difference measurement, so a queried batch can be checked against its own records rather than against a generic specification sheet. Die and mold manufacture takes around 10 to 15 days, with production following in about 15 to 20 days. Standard lengths are 5.8 to 6.0 meters, minimum order quantity is 500 kg per profile, and profiles are packed in brown paper for surface protection in transit. Send your drawings and the exposure conditions the frame has to live with, and we will confirm alloy, coating grade and color before anything is cut.
Q: What does the powder coating actually protect against?
A: The cured powder film does three jobs at once: it provides the color, it blocks moisture and oxygen from reaching the aluminum substrate, and it resists sunlight without degrading. Adhesion is rated Grade 0, salt spray testing runs to at least 1000 hours without corrosion, and the formulation is designed to hold color for more than ten years of UV exposure without chalking, so the frame keeps both its appearance and its corrosion protection on exposed elevations.
Q: Can you match a specific RAL color or a physical sample?
A: Yes. We offer RAL color matching plus textured and metallic finishes, and we can work from a physical sample or a color reference you supply. All profiles in an order are pretreated, sprayed and cured together, which is the practical way to keep the outer frame, sashes, glazing beads and trims consistent with each other. We confirm the color on a sample length for your approval before full production starts.
Q: Do you develop new dies from our drawings?
A: We accept DWG, STEP and PDF files and carry OEM and ODM projects through from drawing to finished profile. Every mold design is reviewed by our engineers for manufacturability before the die is cut, so issues such as an unworkable screw boss or a corner that will not crimp are caught on paper. Die manufacture takes roughly 10 to 15 days, with production following in about 15 to 20 days.
Q: How is quality traced through the order?
A: Records follow the material from raw aluminum ingot spectral analysis, through extrusion and heat treatment, to pretreatment, coating and final measurement of film thickness and color difference. That means a queried batch can be checked against its own process data rather than against a generic specification sheet. Inspection results are issued with the shipment so your quality team can verify alloy, hardness, coating thickness and color against the agreed values.
Q: Which finish do you recommend for exterior window frames?
A: Anodizing AA10 or AA15 is our standard for exterior work and the finish most of our window customers specify. Powder coating is quoted per job rather than stocked.
Q: Can you match a colour sample?
A: Send the sample or the RAL reference and we quote against it. Colour is approved on a sample before the batch runs.
Q: What is the minimum order?
A: 500 kg per section, whether or not a new die is required.

=== Powder Coated Window and Door Profiles ===
URL: https://www.linkedalu.com/products/architectural-aluminum/windows-doors/powder-coated-window-door-profiles.html
Summary: In-house extruded and powder coated aluminum window, door and curtain wall profiles, with graded resins for 10, 15 and 20+ year durability, RAL color matching and PA66-GF25 thermal break sections.
- Alloy & Temper: 6063-T5 architectural grade (6061-T6 and 6005A-T6 available for structural sections)
- Hardness: ≥8 HW (Webster)
- Surface Finish: Powder coating to RAL, textured and metallic finishes; Qualicoat framework used as coating quality reference
- Coating Thickness: 60-120 µm depending on grade and specification
- Durability Tiers: 10 / 15 / 20+ year architectural tiers across standard, weather-resistant, super-durable and PVDF powders
- Thermal Break: PA66-GF25 glass-fiber reinforced polyamide barrier, crimped into knurled channels
- Profile Range: Outer frame and sash extrusions, mullions, transoms, thermal break sections, glazing beads, sub-frames, coupling profiles
- Curing: Multi-stage chemical pretreatment; electrostatic powder application; oven curing at 180-200 °C
- Standard Length: 6.0 m
- MOQ: 500 kg per profile
Powder Coated Aluminum Profiles for Window, Door and Curtain Wall Systems Powder coated window and door profiles in 6063-T5, coated 60–120 µm to RAL, covering outer frames, sashes, mullions and thermal break sections. 6.0 m lengths, 500 kg per profile. We extrude, pretreat and powder coat aluminum architectural profiles in-house for high-performance window, door and curtain wall systems. The range covers outer frame and sash extrusions, mullions and transoms, thermal break sections with a PA66-GF25 polyamide barrier, glazing beads, sub-frames and coupling profiles. One supplier, one process chain, one color reference across every container shipped. Send architectural CAD drawings and we manage the rest: custom die cutting, precision extrusion, multi-stage chemical pretreatment, automated electrostatic powder application, oven curing and laboratory testing. You choose the target RAL color, the texture finish and the durability grade, and we deliver profiles matched to your physical sample and consistent from the first container to the last. The Reality of Architectural Coatings Two suppliers can quote you powder coated aluminum windows. One uses a standard polyester resin that chalks and fades within three years facing direct sunlight. The other uses a super-durable resin that holds its gloss and color for fifteen years. Both look identical on day one. You find out which one you bought when the sun and the salt air have done their work. The Resin Chemistry Drives UV Longevity Powder coating is a dry plastic powder sprayed electrostatically onto aluminum and then baked at 180 to 200 °C. The powder melts, flows out into a continuous film and crosslinks into a hard coating that provides color, seals the metal from moisture and oxygen, and resists sunlight. How well it resists sunlight depends on the resin, because resin is the backbone of the formulation. If the resin breaks down under UV, the coating chalks, fades and eventually stops protecting the aluminum underneath. Powder Grade Resin Type Outdoor Life (Typical Warranty) Where It Belongs Standard polyester Standard polyester resin, TGIC or HAA cured 1-3 years outdoors / 10+ years indoors Interior doors, interior partitions, decorative trim Weather-resistant polyester Modified polyester with UV stabilisers 5-10 years outdoors Standard residential windows and doors, balcony railings Super-durable Super-durable polyester for facade exposure 15 years tier Exterior window and door frames, curtain wall components PVDF Fluoropolymer-based powder 20+ years tier High-exposure facades, coastal and high-UV projects We publish these as durability tiers rather than as a single number for all powder, because the coating on an interior partition door and the coating on a coastal curtain wall have nothing in common except the color. Matching the grade to the exposure is the difference between a frame that still looks new at year twelve and one that is being repainted at year four. Pretreatment and Application Coating adhesion depends more on pretreatment than on the powder. Profiles pass through a multi-stage chemical pretreatment that removes extrusion oils, etches the surface and builds a conversion layer for the powder to bond to. The powder is then applied electrostatically so it wraps the profile including the return flanges and the inside of the glazing groove, and the section is cured in an oven at 180 to 200 °C until the film is fully crosslinked. Coating thickness is typically 60 to 120 µm depending on the grade and the specification agreed, and the Qualicoat framework is used as the reference for coating quality on facade-grade work. Thermal Break and System Profiles Where the frame separates a conditioned interior from the weather outside, the metal path is interrupted by a PA66-GF25 polyamide strip that is crimped into knurled channels on both halves of the profile. Glass-fiber reinforcement gives the barrier the mechanical strength to carry shear between the inner and outer sections, while the polyamide itself conducts far less heat than aluminum does. That is what keeps the inner face warm enough to avoid condensation and stops the frame from acting as a radiator in winter. Choosing a Grade for Your Project Interior partition and decorative trim: standard polyester, color and cost matter more than UV stability Residential windows and doors in temperate climates: weather-resistant polyester with UV stabilisers Exterior frames and curtain wall components: super-durable polyester for facade exposure Coastal, desert and high-altitude sites: PVDF powder where color retention over two decades is required Standard length is 6.0 meters, minimum order quantity is 500 kg per profile, and profiles are packed in shrink film for protection during shipping. Tell us the exposure the frame will see, the color reference and the durability tier you are working to, and we will confirm the profile, the pretreatment sequence and the coating specification before production begins.
Q: Why does the powder grade matter more than the color?
A: Color is the part you can see on day one, and it is the part every supplier can match. What differs is the resin that carries that color. A standard polyester resin can chalk and fade within about three years facing direct sun, while a super-durable or PVDF resin holds gloss and color for fifteen to twenty years. The coatings look identical when new and behave nothing alike after a few summers.
Q: Which powder grade should I use for a coastal building?
A: For coastal sites, high-altitude locations and desert projects we recommend the PVDF fluoropolymer grade, which sits in the 20+ year durability tier. Standard and weather-resistant polyester grades are cost-effective for interior and temperate residential work, but airborne chloride and intense UV accelerate chalking and gloss loss. Grade selection plus adequate pretreatment is what keeps a coastal frame looking new rather than fading within a few seasons.
Q: How does the PA66-GF25 thermal break work?
A: The polyamide strip is crimped into knurled channels in aluminum, forming a structural bridge between the inner and outer halves of the profile. Glass fiber reinforcement gives it the shear strength to hold the frame rigid, while polyamide conducts far less heat than aluminum. The result is a warm inner face that resists condensation and a frame that does not act as a radiator, with no loss of mechanical performance.
Q: What file formats and information do you need to quote?
A: Send architectural CAD drawings, ideally in DWG, STEP or PDF, with the cross-section, alloy and temper required for each profile. Tell us the exposure conditions, the target RAL color, the texture finish and the durability tier you are working to, plus quantities and any cutting or machining needed. We review the die design for manufacturability and confirm pretreatment and coating specification before production.
Q: Do you machine the hinge and lock pockets before coating?
A: Yes. Machining happens before the coating line, so the cut edges are covered and the hardware fits without touching up the finish afterwards.
Q: What is the difference between this page and the frame profile page?
A: This page covers the full door leaf and frame set, including the machining for hardware. The frame page covers the outer frame sections on their own.
Q: What is the minimum order?
A: 500 kg per section, whether or not a new die is required.

=== Aluminum Heat Sink Extrusions for LED and Power Electronics ===
URL: https://www.linkedalu.com/products/industrial-aluminum/aluminum-heatsinks/aluminum-heat-sink-extrusions-led-power.html
Summary: Custom extruded aluminum heat sink profiles in 6063-T5, engineered from your drawing or thermal spec. Fin pitch to 1.5 mm, skived tips to 0.2 mm, milled mounting faces at ≤0.05 mm flatness. Send the fin pitch, base thickness and mounting pattern, and the quotation comes back with a die and a price.
- Alloy & Temper: 6063-T5 (standard); 6061-T6 and 6005A-T6 available
- Hardness: 14 ± 2 HW
- Thermal Conductivity: ~200 W/m·K (6063-T5); ~230 W/m·K (pure aluminum 1050/1060)
- Fin Pitch: ≥2.5 mm standard; 1.5 mm minimum, fin-height dependent
- Fin Height & Tip: Up to 50 mm, 80 mm with die design; tip ≥0.5 mm extruded, 0.2–0.4 mm skived
- Base Thickness: 2 mm – 20 mm
- Profile Width: 10 mm – 300 mm; wider sections on a large press
- Surface Finish: Mill (emissivity ~0.05–0.10), black anodized (0.85–0.90), hard anodized (~0.80), sandblasted
- Secondary Machining: Cut ±0.1 mm; milled mounting flatness ≤0.05 mm; tapping M2.5 – M6
- Length, MOQ & Standards: 6 m standard, cut-to-length from 100 mm; MOQ 500 kg; ISO 9001:2015
Custom Heatsink Extrusions Built to Your Thermal Spec Aluminum heat sink extrusions in T5 and T6 for CPU coolers, LED drivers and power supplies: fin pitch down to 1.5 mm, skived tips to 0.2 mm, base milled to 0.05 mm flatness, 500 kg per profile. We extrude aluminum heat sink profiles to the exact cross-section your thermal design calls for. You can send a 3D drawing, a cross-section sketch, or simply the numbers: heat load in watts, ambient temperature, maximum junction temperature and cooling mode. Our die engineers evaluate fin height, fin-to-fin ratio, pitch, base thickness and tolerance against what is actually extrudable in 6063-T5 at production speed. If a feature will not fill properly, or the die tongue will not survive the run, we say so before anyone cuts steel, and we propose an alternative that delivers the same thermal performance. Typical applications include LED street lights, high bay and flood luminaires, power inverters, UPS systems, variable frequency drives, CPU and GPU coolers, and EV onboard chargers. Why 6063-T5 Is the Default Alloy Pure aluminum conducts heat better, at roughly 230 W/m·K against about 200 W/m·K for 6063, but it is too soft. Extrude thin fins from 1050 or 1060 and they fold over coming out of the die, or bend the first time someone handles the part. 6063-T5 gives you about 85% of the thermal conductivity with enough mechanical strength to manufacture and use the component. That is the trade-off the industry has settled on, and it is our standard for heat sinks. 6061-T6 is available where the sink also acts as a structural member or has to be welded, and 6005A-T6 suits welded frame assemblies. Fin Geometry: What a Heatsink Extrusion Can Actually Hold Fin density limits depend on fin height, not pitch alone. A fin under 10 mm tall can hold a tight 1.5 to 2 mm pitch. Push fin height to 50 mm and you need roughly 3 to 5 mm spacing, because the die steel that forms each gap needs enough material to survive extrusion pressure without cracking. Practical ranges: fin pitch from 2.5 mm standard with a 1.5 mm minimum; fin height up to 50 mm, and 80 mm with careful die design; fin tip thickness of 0.5 mm or more as-extruded; base thickness from 2 mm to 20 mm; profile width from 10 mm to 300 mm, with wider sections requiring a larger press. If your design sits outside these ranges, send the drawing anyway. Sometimes a small change to corner radii or fin taper is all it takes to bring it within extrudable limits. Three Ways We Form Fins in an Extruded Heatsink Direct extrusion is the workhorse. Fins and base come out as one solid piece of aluminum, with no joint and no thermal interface resistance between fin and base. It suits fin heights under 50 mm and tip thickness above 0.5 mm, at the lowest cost and highest production speed. CNC skiving covers what extrusion cannot. We extrude a blank with thicker fins and slice them down on a skiving machine to between 0.2 mm and 0.4 mm. This is how high-performance CPU coolers and server heat sinks are produced. Bonded or inserted fins serve very large heat sinks, such as industrial drives, welding machines and traction inverters, where fin height exceeds what is practical in a single extrusion. Individual fins are bonded or mechanically pressed into a grooved base plate, giving large surface area without the die complexity and cost of a giant profile. Surface Finish and Radiated Heat A heat sink both convects and radiates, and the radiation side is often overlooked. Mill finish has an emissivity of roughly 0.05 to 0.10, which is adequate for enclosed forced-air cooling. Black anodizing reaches about 0.85 to 0.90 and delivers a real, measurable 10 to 15% gain in natural convection; in forced air at high velocity the gap narrows to roughly 3 to 5%. Hard anodizing gives around 0.80 together with electrical isolation and a very durable surface. Sandblasted plus anodized exceeds 0.90. A simple rule: if the heat sink relies on natural convection, anodize it black. Anodizing is run in-house in black, natural silver, champagne and bronze. Machining, Flatness and Heat Pipe Grooves As-extruded mounting surfaces run about 0.2 mm per 100 mm of flatness, which is good enough for many applications. Power electronics customers usually need better, so we mill the base after extrusion and hold flatness to 0.05 mm or less across the mounting face, flat enough for a thin and uniform thermal interface layer. Secondary work in our own CNC shop includes cut-to-length at 0.1 mm, drilling and tapping from M2.5 to M6, deburring and cleaning so parts arrive ready to handle. We can also extrude a semi-circular or circular groove into the base to accept a heat pipe, in the common diameters of 6 mm, 8 mm and 10 mm, formed in the same pass as the profile. Ordering Minimum order is 500 kg per profile. Heat sink profiles are light per meter, so that is usually a meaningful batch; prototyping from an existing die can run smaller. Standard length is 6 m cut to length from 100 mm, with up to 7 m extruded. Profiles are protected with in-line PE film and packed on pallets. Production runs under an ISO 9001:2015 quality system.
Q: Why do you extrude heat sinks in 6063-T5 instead of pure aluminum?
A: Pure aluminum conducts heat at about 230 W/m·K against roughly 200 W/m·K for 6063, but it is too soft to hold thin fins. Extruded 1050 or 1060 fins fold over at the die exit or bend during handling. 6063-T5 delivers about 85% of the conductivity with the mechanical strength needed to manufacture and use the part, which is why it is the industry standard for extruded heat sinks.
Q: What is the tightest fin pitch you can hold?
A: It depends on fin height rather than pitch alone. Fins under 10 mm tall can hold a pitch of 1.5 to 2 mm. At 50 mm fin height you need roughly 3 to 5 mm spacing, because the die steel forming each gap has to survive extrusion pressure without cracking. We check your target geometry against our die strength models and give you a straight answer before tooling is cut.
Q: Can you produce 0.3 mm fin tips?
A: Not reliably by direct extrusion. The die tongue that forms each fin gap would be too fragile for production. Instead we extrude a blank with thicker fins and skive them down to a final thickness of 0.2 to 0.4 mm. If your thermal simulation requires 0.3 mm tips, skiving is the route we recommend.
Q: How flat can you machine the mounting face?
A: As-extruded flatness is around 0.2 mm per 100 mm. That is adequate for many applications, but power electronics generally need better. We mill the base after extrusion and hold flatness to 0.05 mm or less across the mounting face, which keeps the thermal interface layer thin and uniform under an IGBT module or an LED board.
Q: What fin pitch can you extrude for a heatsink?
A: Fin pitch down to 1.5 mm, with skived tips at 0.2 mm where the thermal spec needs thinner geometry. Anything tighter than that is a machining job, not an extrusion.
Q: Do you make heatsink extrusions for LED street lights?
A: Yes. LED luminaires are one of the two largest uses of this profile family, alongside power electronics. Send the LED board layout and we size the base and fin field around it.
Q: What is the minimum order for a custom heatsink extrusion?
A: 500 kg per section, whether or not a new die is required. Mixed sections can be consolidated into one shipment.

=== Extruded Heat Sinks for Inverters, IGBTs and EV Batteries ===
URL: https://www.linkedalu.com/products/industrial-aluminum/aluminum-heatsinks/extruded-heat-sinks-power-electronics.html
Summary: An engineering guide to extruded heat sinks and friction stir welded cold plates for string inverters, IGBT modules and EV battery packs, covering alloy selection, fin geometry, base flatness and leak testing.
- Alloy & Temper: 6063-T5 (heat sinks), 6061-T6 (structural / high pressure), 6005A-T6 (welded frames)
- Thermal Conductivity: ~200 W/m·K (6063-T5)
- Yield Strength: 145 MPa (6063-T5)
- Profile Width: 10 mm – 300 mm standard; up to 420 mm on a large press
- Fin Height & Pitch: Up to 50 mm standard, 80 mm with die design; pitch ≥2.5 mm, 1.5 mm minimum
- Base Thickness: 2 mm – 20 mm; 8–15 mm for IGBT mounting
- Mounting Surface Flatness: ≤0.05 mm CNC milled; roughness Ra 1.6 µm or finer
- Cold Plate Channels: 3–8 mm internal diameter; 0.5–1.5 MPa working, burst ≥3.0 MPa
- Leak Test: 250 kPa for 60 s, leakage below 30 Pa
- Tolerance, Length & MOQ: EN 755-9; 6 m extruded, cut from 100 mm; MOQ 500 kg
Designing an Extruded Heatsink for Power Electronics Aluminum extrusion handles power electronics cooling, from 10 kW string inverters up to EV battery packs, but only when the profile is designed around both the heat path and the limits of the extrusion press. The right approach depends on what you are cooling: a passive IGBT heat sink, a solar inverter housing, or a liquid-cooled battery cold plate. Start with the thermal specification. Send us heat load in watts, ambient temperature, maximum junction temperature and the cooling mode, whether natural convection, forced air or liquid. If you have a CFD model, send it. If you do not, tell us the power and we will work backward to a profile. Alloy Selection for Power Electronics 6063-T5 is the standard for extruded heat sinks, with a thermal conductivity of roughly 200 W/m·K and a yield strength of about 145 MPa. 6061-T6 is used where the profile is structural or sees high internal pressure, and 6005A-T6 where the assembly is welded. Profile widths run from 10 mm to 300 mm on standard presses and up to 420 mm on a large press. Fin Geometry and Base Thickness Fin pitch is normally 2.5 mm or wider, with 1.5 mm as the practical minimum, and fin height goes up to 50 mm as standard or 80 mm with dedicated die design. Base thickness runs from 2 mm to 20 mm; for IGBT mounting, a base of 8 mm to 15 mm is typical because it spreads heat laterally before the fins remove it. Tolerance is held to EN 755-9, with as the legacy German reference. IGBT Module Mounting: What the Base Must Do The base is a thermal interface, and its geometry matters as much as its alloy. Surface flatness: 0.05 mm or better. Every 0.01 mm of extra gap adds roughly 0.5 to 1.0 K of thermal resistance. Surface roughness: Ra 1.6 µm or finer, so thermal paste spreads evenly without pooling. Flatness method: CNC face milling after extrusion. As-extruded flatness of about 0.2 mm per 100 mm is not good enough for a semiconductor interface. Where an inverter concentrates heat at specific locations instead of spreading it evenly, we can extrude a semi-circular groove into the base for a heat pipe, in the common diameters of 6 mm, 8 mm and 10 mm. Industrial VFDs and UPS Systems For industrial drives and UPS units, power dissipation per module is typically 50 to 150 W, with total heat sink dissipation of 200 to 800 W depending on drive rating. These applications tend toward larger profiles, thicker bases and machined mounting surfaces with precisely located hole patterns. Aluminum Cold Plates for EV Battery Cooling Liquid cooling moves the heat load to a cold plate with internal channels. Extruded channel diameters run from 3 mm to 8 mm. The channels are sealed at the ends, and friction stir welding is the default for EV cold plates: a rotating tool plunges into the aluminum and stirs the metal into a solid-state bond with no filler material and no porosity, which survives thermal cycling. Cold plates operate at 0.5 to 1.5 MPa working pressure with a burst rating of at least 3.0 MPa. Leak Testing and Surface Finish Every cold plate is pressure tested at 250 kPa for 60 seconds with leakage below 30 Pa. Surface finishes include mill, black anodized with an emissivity of 0.85 to 0.90, hard anodized and sandblasted. Anodizing thickness is 10 to 25 µm per Qualanod practice. Ordering and Lead Times Standard length is 6 m extruded, cut to length from 100 mm. Minimum order is 500 kg per profile. Lead time to first sample on a new die is 10 to 15 working days, and 7 to 10 working days for repeat orders. Send the drawing early so a manufacturability review happens before tooling is cut. Production runs under an ISO 9001:2015 quality system.
Q: Can extruded aluminum heat sinks handle inverter cooling?
A: Yes, from roughly 10 kW string inverters up to EV battery packs, provided the profile is designed around the heat load and the limits of the extrusion press. Industrial VFD and UPS modules typically dissipate 50 to 150 W each, with total heat sink dissipation of 200 to 800 W depending on drive rating. Send heat load, ambient temperature, maximum junction temperature and cooling mode.
Q: What flatness does an IGBT mounting surface need?
A: 0.05 mm or better, with a surface roughness of Ra 1.6 µm or finer. Those values keep the thermal paste layer thin and uniform. As-extruded flatness of about 0.2 mm per 100 mm is not good enough for a semiconductor interface, so the base is CNC face-milled after extrusion. Every 0.01 mm of extra gap adds roughly 0.5 to 1.0 K of thermal resistance.
Q: How are liquid cold plate channels sealed?
A: Friction stir welding is the default for EV cold plates. A rotating tool plunges into the aluminum at the channel ends and stirs the metal into a solid-state bond with no filler material and no porosity, so it withstands thermal cycling. Extruded internal channels run 3 to 8 mm in diameter, and cold plates operate at 0.5 to 1.5 MPa with a burst rating of at least 3.0 MPa.
Q: What lead time applies to a new heat sink die?
A: For a new die, allow 10 to 15 working days to first sample, and 7 to 10 working days for repeat orders. Minimum order is 500 kg per profile. Send your drawing early if the project schedule is tight, so that a manufacturability review of fin geometry and base thickness happens before tooling is cut.
Q: What base thickness do IGBT modules need?
A: Enough to spread heat across the module footprint without adding thermal resistance of its own. Send the module outline and mounting pattern and we size the base from the spreading requirement, not from stock.
Q: Do you leak test cold plates?
A: Yes. Every cold plate is pressure tested before it leaves the plant, and the test figures travel with the order on the inspection record.
Q: Can you supply the heatsink and the cold plate for one inverter programme?
A: Yes, on one shipment, which keeps flatness and finish consistent across both parts.

=== EV, Servo and Stepper Motor Housings ===
URL: https://www.linkedalu.com/products/industrial-aluminum/electric-motor-housings/ev-servo-motor-housings.html
Summary: Extruded aluminum motor housings with integral cooling fins for servo, stepper, spindle and EV traction motors. Bores held to 0.05 mm roundness, spigots machined in a single setup, from blanks to finished housings.
- Alloy & Temper: 6063-T5 (standard); 6061-T6 for high-stress and welded housings
- Hardness: ≥15 HW
- Bore Roundness: ≤0.05 mm standard; ≤0.02 mm with honing
- Bore Surface Finish: Ra 1.6 µm standard; Ra 0.8 µm or better on request
- Spigot Concentricity to Bore: ≤0.03 mm standard; ≤0.01 mm on request
- Wall Thickness Variation: Within ±5% of nominal
- Cut Length & End Face Squareness: ±0.10 mm; squareness 0.05 mm per 100 mm diameter
- Surface Finish: Black anodized, hard anodized, natural anodized, or powder coated
- Standard Length & Tapping: 4.0 m extruded; tapped holes 6H class (5H on request)
- MOQ, Lead Time & Standards: 500 kg on a new die; new die 15–20 working days, sample housing ≈20–25 working days; ISO 9001:2015
Extruded Shells With Integral Cooling Fins Die casting gives you complex shapes but charges long lead times and a tooling bill that makes small production runs unworkable. Off-the-shelf extruded tube leaves you bolting on separate heat sinks and machining every feature from solid. We take a third route: we extrude custom aluminum motor housings, round, square or fully custom in cross-section, with the cooling fins formed in the same pass. The housing is then machined so the inner bore and end faces meet the tolerances your rotor and end bells demand. Fins That Perform, Not Just Look the Part Tall, thin fins push against the physical limits of hot aluminum flowing through a die tongue. The die steel has to be thin enough to form the gap between fins and strong enough to survive extrusion pressure at around 500 °C. When the ratio of fin height to fin thickness exceeds roughly 15:1, standard die design and standard die steel stop holding up, and you get underfilled fins and broken tips. We treat the thermal specification as a design input rather than an afterthought. Small changes to root radius, tip taper and wall transition can reduce die tongue stress by 20 to 30% while keeping the same total surface area, and we quantify those changes so your thermal engineer can verify them. When direct extrusion cannot reach the required fin geometry, we extrude a blank with thicker fins and skive them down on a CNC machine to a final thickness of 0.2 to 0.4 mm. Die tongues are cut from H13 or SKD61 hot-work steel, vacuum hardened and triple tempered, with tongue geometry checked every production shift. Bores That Stay Round A bore that is not round produces a motor that whines under load, with an air gap that varies around the circumference. The usual cause is wall thickness eccentricity: during cooling and straightening, the side with tall fins cools faster than the smooth side, setting up residual stress that releases unevenly when the bore is machined. We address it at three stages. The die is designed so the inner mandrel and outer die ring align precisely, and wall thickness eccentricity is monitored, holding wall variation within 5% of nominal on a typical housing. Every bar is tension-stretched after extrusion to 1 to 3% permanent elongation to pull out residual stress before machining, and for servo or spindle motors we can add a thermal stress-relief cycle. Finished housings are bored and spigot-faced in a single setup so concentricity between bearing seat and stator bore comes from the machining sequence rather than luck. Cost: Extrusion Versus Die Casting For tubular motor shells with external fins, extrusion tooling costs a fraction of die casting tooling and the die lead time is roughly half. We set the minimum order at 500 kg on a new die, which is enough for a serious pilot run or a small production batch: a typical motor housing weighs a few kilos per meter. The tooling fee is charged upfront and refunded in full once cumulative orders reach an agreed volume. Because we handle sawing, boring, spigot machining, drilling and tapping in-house, you qualify one supplier instead of two, with a single drawing and one batch of finished housings. Alloy and Surface Finish Guide 6063-T5 is the standard for most motor housings. It extrudes well, anodizes evenly and handles the thermal and mechanical loads of servos, steppers and general industrial motors. 6061-T6 suits high-stress applications such as large EV motors, motors welded into a frame, or housings that double as structural members; it is roughly 50% stronger than 6063-T5 and takes welding without losing significant strength in the heat-affected zone. Black anodizing is the industry standard for servo and stepper motors, boosting radiation heat transfer by 10 to 15% and providing good electrical insulation. Hard anodizing gives a thick, dense oxide layer with high dielectric strength for spindle motors. Natural anodizing is the cost-sensitive option, and powder coating fully encapsulates outdoor or marine-duty motors. Tolerances and Delivery Options Bore roundness is held to 0.05 mm as standard and to 0.02 mm with honing, with bore surface finish at Ra 1.6 µm or better on request. Spigot concentricity to bore is 0.03 mm, or 0.01 mm on request. Cut length is 0.10 mm, end face squareness 0.05 mm per 100 mm of diameter, and tapped holes are 6H class as standard. We ship motor housings three ways. Extruded blanks are straightened and cut to rough length for customers who machine in-house, at the lowest cost. Pre-machined blanks are cut to finish length, rough-bored and faced square. Finished housings are fully machined with precision bored bore, cut spigot and register faces, drilled and tapped mounting holes, cable gland cross-holes and engraved serial numbers, cleaned and deburred. Lead time for a new die is 15 to 20 working days, plus 3 to 5 days for trial extrusion and sample machining.
Q: Can you check whether our fin design is extrudable?
A: Yes. Send the cross-section with fin dimensions, or the thermal specification. We assess it against our die strength models and give one of three answers: it works as drawn, it works with specific small changes to root radius, tip taper or wall transition, or we recommend skiving the fin tips. Changes we propose can cut die tongue stress by 20 to 30% at the same surface area.
Q: Can extrusion replace die casting for motor housings?
A: For tubular housings with external fins, extrusion is often the better process: lower tooling cost, faster die changes, and no porosity that shows up as leaks or thermal hot spots. The trade-off is that extrusion cannot produce complex side bosses or deep undercuts the way die casting can. If your housing is essentially a cylinder with fins, extrusion is almost certainly the right call.
Q: How do you guarantee bore roundness?
A: We control the three causes: wall thickness eccentricity during extrusion, residual stress from cooling, and misalignment during machining. Wall variation is held within 5% of nominal, every bar is tension-stretched 1 to 3% after extrusion, and for servo or spindle housings we can add a thermal stress-relief cycle. Finished housings are bored and spigot-faced in one setup, holding roundness to 0.05 mm or better.
Q: Do you make water-cooled motor housings?
A: We can extrude straight cooling channels inside the housing wall, running longitudinal passages parallel to the bore, which work well for simple water jackets. For complex serpentine channels, a practical alternative is to extrude a thicker wall, machine the channels into it, and seal them with a welded or O-ringed outer sleeve. Send your cooling requirement and we will propose the most practical route.
Q: Do you bore the housing and machine the end caps?
A: Yes. The bore, the end-cap register and the fixing holes are machined after extrusion so the stator fit is held on the finished part.
Q: Which alloy for a motor housing?
A: 6063-T5 for most housings because it extrudes the fin detail cleanly, 6061-T6 where the housing is also a structural member.
Q: What is the minimum order?
A: 500 kg per section on the extrusion; machining is quoted per drawing.

=== LED Light Housing Extrusion Profiles ===
URL: https://www.linkedalu.com/products/industrial-aluminum/led-lightings/led-light-housing-extrusion-profiles.html
Summary: Custom LED aluminum extrusion profiles machined to your drawing: linear light housings, T5/T8 tube shells and heat sinks, architectural strip channels, track rails and wall washer bodies, finished in a single anodizing batch.
- Alloy & Temper: 6063-T6; 6063-T5 and 6061-T6 available
- Hardness: ≥11.5 HW
- Standard Length: 3 m extruded; cut to fixture length at ±0.1 mm
- Surface Finish: Silver or black anodizing in a single batch; powder coat or PVDF available
- Diffuser Groove Tolerance: ±0.15 mm on groove width and depth, verified with your cover sample
- End-Cap Holes: CNC thread-milled, 6H class; blind depth = screw length + 2 mm clearance
- Mounting Holes: CNC drilled, position ±0.15 mm
- Straightness: ≤0.5 mm/m (1.5 mm maximum deviation over a 3 m housing)
- Fabrication: Cut, drilled, tapped, end-milled and labeled; in-line PE protective film
- MOQ: 500 kg on a new die; 200 kg from an existing die
LED Housing Profiles Engineered for Your Fixture LED housing profiles are extruded in 6063-T6 at 3 m standard length, cut to fixture length at ±0.1 mm, with straightness held to 0.5 mm per metre. 500 kg per profile. We extrude, machine and finish custom aluminum profiles specifically for the LED lighting industry. Send us a cross-section CAD drawing or a physical sample. We cut the die, extrude the profile, cut bars to your exact fixture lengths, CNC drill and tap the mounting holes, anodize or powder coat the entire batch, and ship ready-to-assemble components to your factory. The profile you receive is the profile you designed, with your groove dimensions, your wall thicknesses and your screw boss locations. We do not push a standard off-the-shelf die when a fixture needs custom engineering. Anodizing Consistency Across LED Housing Batches The most common late complaint in LED housings is color drift. A lighting company orders a batch of black anodized housings, everything looks right, and six months later a reorder shows up slightly warmer or slightly greyer on the same ceiling. The cause is almost never the anodizing line on the day of production. It is that the two batches ran weeks or months apart, on different shifts, with small differences in dye concentration, tank temperature, current density or billet chemistry. Any one of those shifting a few percent changes the final tone of black. Every profile in your order, regardless of how many cross-sections or lengths it contains, is extruded from the same billet heat and anodized in the same tank run. For reorders we keep a physical master sample and the Lab values from the first production batch, run a short trial piece and match it before committing the full run. If you are switching suppliers, send a sample of your current housing and we will match it. Thread-Milled End-Cap Holes An LED housing has blind holes drilled and tapped into each end, and an end-cap screw strips there at the very end of assembly, when the PCB is already mounted and the wiring is already run. Stripped threads usually come from a worn tap cutting an undersized thread, or a blind hole too shallow so the screw bottoms out before the head seats. We thread-mill these holes rather than tapping them. A thread mill cuts the thread profile along a helical path, producing a smoother, more consistent thread with tighter tolerance and no torn crests. We hold 6H class on every hole and set blind depth to your screw length plus at least 2 mm of clearance. Where a fixture has a removable end cap for driver access, we can install stainless steel wire thread inserts at the factory so the screw threads into hardened steel for the life of the fixture. Diffuser Groove Fit, Verified With Your Cover The groove that holds the polycarbonate or acrylic diffuser is the most critical dimension on an LED housing. Too narrow and the cover bows or will not seat. Too wide and it rattles, leaks light or falls out in transit. We hold groove opening to 0.15 mm on both width and depth, but the real check is physical: before the die is finalized we ask for a short sample of the cover you use, extrude a trial section and snap the cover into it. If the fit is too stiff, too loose or does not click, we adjust the groove in the die. During production the groove is gauged on a sample from every 50 bars, so drift from die bearing wear is caught early. Straightness Over Long Fixture Lengths A 1.5 m linear light on a wall or ceiling shows a bow immediately. The human eye picks up a 2 mm deviation over that length. Profiles leave the press with internal stress, and if it is not relieved the bar looks straight when cut and bows later as the stress relaxes. Every profile passes through a tension stretcher after extrusion, pulling the material past yield by 1 to 3% permanent elongation to equalize internal stress. We hold straightness at 0.5 mm per meter or better, and every bar is rolled on a flat inspection table before packing. For housings 2.5 m and longer we check section rigidity at die design and recommend wall thickness adjustments if the section would be too flexible. Cut to Fixture Length: The Hidden Cost of Cutting In-House Buying 6 m bars and cutting in-house looks cheaper per meter, but add the kerf loss from every saw cut, the offcuts too short to use, bars scrapped because the saw was not square, the labor hours feeding a saw instead of assembling fixtures, and the floor space. A lighting factory using 10 tons of aluminum a month at a 5% sawing scrap rate discards 500 kg of finished, anodized aluminum every month. We supply profiles cut to your exact fixture lengths at 0.1 mm, with no kerf loss, no offcuts and no miscuts. Ordering Machining and finishing cover precision cut-to-length at 0.1 mm, CNC thread-milled end-cap holes at 6H class, CNC-drilled mounting holes at 0.15 mm position, the verified PC cover groove, silver or black anodizing in a single batch with powder coat or PVDF available, in-line PE film, and packaging by fixture type and length or kitted one fixture per pack. Minimum order is 500 kg on a new die, or 200 kg from an existing die.
Q: Our black anodized housings drift in shade between orders. Can you lock the color?
A: Yes. On the first production run we keep a physical master sample and record the Lab values. Every reorder is matched against that sample, and we run a short trial piece before committing the full batch. All cross-sections in one order are extruded from the same billet heat and anodized in the same tank run. If you are switching from another supplier, send a sample of the housing you use now.
Q: End-cap screws on our current housings strip about once every hundred units. How do you prevent that?
A: We thread-mill the holes instead of tapping them. A thread mill cuts the thread profile along a helical path, producing a smoother and more consistent thread with no torn crests, and we hold 6H class on every hole. Blind depth is set to your screw length plus at least 2 mm of clearance, so the thread engages fully before the screw bottoms out.
Q: Our diffuser supplier changed their cover slightly and now the fit is different. Can you adjust?
A: Yes. Send a sample of the new cover. We measure it, adjust the groove dimensions in the die if needed, run a trial section and confirm the fit with you before production ships. This is a routine part of LED manufacturing, and it is far easier to correct in the die than to sort fixtures and rework covers on the assembly line.
Q: Can you hold straightness over a 3-meter housing?
A: We hold 0.5 mm per meter, so a 3 m housing stays within 1.5 mm of straight. Profiles are tension-stretched after extrusion to 1 to 3% permanent elongation, which releases the internal stress that otherwise makes a cut bar bow over time. For housings 2.5 m and longer we check section rigidity at die design and recommend wall thickness changes if needed.
Q: Can you match the anodized colour between repeat orders?
A: Within a batch, yes, because the housings are anodized together. Across batches we hold a master sample and check against it, so a reorder does not arrive a shade off.
Q: Do you machine the end-cap holes?
A: Yes, thread-milled to your drawing so the end caps screw on without rework. Tell us the thread and the torque you expect.
Q: What wall thickness do you recommend for a linear housing?
A: From 0.8 mm, but the right figure depends on span and how the fixture is mounted. Send the fixture length and fixing points and we will size it.

=== LED Channel and Rail Profiles ===
URL: https://www.linkedalu.com/products/industrial-aluminum/led-lightings/led-channel-and-rail-profiles.html
Summary: Custom aluminum profiles for LED tube lights, linear fixtures, strip channels and track rails, extruded in 6063-T5 and supplied pre-cut, drilled and tapped in black or silver anodized finish.
- Alloy & Temper: 6063-T5 (standard); 6061-T6 available
- Hardness: ≥8 HW
- Standard Length: 2 m extruded; pre-cut to fixture length
- Surface Finish: Silver or black anodizing; powder coat available
- Profile Types: T5/T8 tube shells, linear channels, wall washers, U/V channels, track rails
- PCB Seat Wall Thickness: 1.0 mm or more recommended to avoid thermal saturation
- MCPCB Seating Face: Extruded flat and process-controlled to prevent micro-gaps under the board
- Snap-Fit Groove: Dimensioned to your diffuser supplier's molded tolerances
- Fabrication: Cut, CNC drilled, tapped and deburred; ready-to-assemble housings
- MOQ & Standards: 500 kg MOQ; ISO 9001:2015 quality system
An LED Extrusion Profile, Not Just an Aluminum Bar When you buy an LED housing profile you are buying a structural component that has to hold a metal-core PCB perfectly flat, grip a polycarbonate cover tight without buckling, run cool for tens of thousands of hours, and still look pristine under a retail showroom spotlight. We extrude it, CNC machine it and anodize it, so you can focus on building the light. The process runs in one line: precision extrusion, in-house CNC machining, dye-controlled anodizing, and a ready-to-assemble housing at the end. LED Channel and Rail Profiles We Extrude T5 and T8 retrofit tubes: heavy-duty cylindrical housings with integrated heat-dissipating channels. Linear pendant and surface channels: architectural-grade profiles with seamless diffuser integration. Wall washers and grazers: angled housings engineered to throw light precisely while concealing the source. U-channels and V-channels: ultra-slim, low-profile tracks for commercial tape light installations. Track light rails: robust rectangular rails with tight internal tolerances for conductive electrical tracks. These are not generic catalog items. The snap-fit groove that holds your PC diffuser has to be dimensioned exactly to the tolerances your cover supplier molds to. The internal screw bosses must align with your molded end caps. The surface where the MCPCB sits must be flat enough to prevent the micro-gaps that trap heat and burn out diodes. Fixing LED Burnout: Thermal Mass and Face Flatness Early LED failure in high-wattage linear fixtures and T8 retrofits is usually a profile problem rather than a diode problem, and the pattern is consistent. The wall where the PCB sits is too thin, often 1.0 mm or less, so the aluminum saturates with heat quickly and junction temperature climbs. The extruded seating face is slightly convex or concave, so the board sits on high points with air trapped between them and heat bottlenecks at the diodes. We hold the seating face flat through die design and process control, and we keep the wall under the MCPCB at a wall thickness that gives the profile enough thermal mass to spread the load before convection removes it. Where a fixture runs hot, we can also increase surface area with finned side walls that double as the visual profile. Profile Reliability Through the Tooling The diffuser groove is dimensioned to your cover supplier's molded tolerances, and the screw boss centers are set to match your molded end caps. We work from your fixture drawings, or, if you are still in R&D without a finalized CAD file, from your PCB width, cover type and mounting constraints. We will sketch a custom cross-section, cut the die, extrude the run, perform secondary CNC fabrication and anodize the batch in a color-matched run. From Drawing or Sketch to Finished Housing Send us your cross-section CAD drawing or a physical sample. If you are still in early R&D without a finalized CAD file, tell us your PCB width, cover type and mounting constraints and we will sketch a custom cross-section for your review. From there the sequence is fixed: cut the die, extrude the run, carry out secondary CNC fabrication, finish the batch in a color-matched anodizing or powder coating run, and deliver components that go straight onto your assembly line. Because extrusion tooling costs a fraction of die casting tooling, a custom LED profile is practical even for a mid-volume fixture program. Standard length is 2 m, but most customers order pre-cut lengths matched to the fixture, which removes saw kerf loss, unusable offcuts and the floor space a saw cell occupies in a lighting factory. Black and silver anodized housings are standard, with powder coat available where a decorative color or textured finish is required. Because every profile in an order is machined and finished together, the components in one shipment match each other in color and in dimension. Fabrication and Delivery Profiles are extruded in 6063-T5 as standard, which anodizes evenly and carries the thermal load of a passive LED fixture. Where a housing also acts as a structural member or has to take welding, we step up to 6061-T6. Standard length is 2 m, and we supply pre-cut, CNC drilled and tapped housings rather than raw bar, because that is how most customers order. Send the fixture drawing with cut lengths and hole positions and we ship components ready for your assembly line. Minimum order is 500 kg, and production runs under an ISO 9001:2015 quality system.
Q: Our LEDs are burning out early and thermal testing shows the housing is not pulling heat away. What causes that?
A: Two profile faults dominate. First, insufficient thermal mass: if the wall the PCB sits on is 1.0 mm or thinner, the aluminum saturates with heat quickly and junction temperature climbs. Second, a convex or concave extrusion face, which leaves micro-gaps under the board and traps heat at the diodes. We hold the seating face flat and keep wall thickness at 1.0 mm or more under the MCPCB.
Q: How do you ensure the diffuser snaps in properly?
A: The snap-fit groove is dimensioned to the tolerances your cover supplier molds to. We work from your fixture drawing, or from your PCB width, cover type and mounting constraints if the design is still in R and D. Groove geometry is confirmed against the cover before the die is signed off, then monitored during production so the fit does not drift as the die bearing wears.
Q: Can you supply pre-cut, drilled and tapped housings rather than raw bar?
A: Yes, and that is how most customers order. Send the fixture drawing with cut lengths and hole positions. We extrude the profile, cut the bars to length, CNC drill and tap the mounting holes, anodize the batch and ship ready-to-assemble components to your factory. Raw bar and 6 m lengths remain available if you prefer to do your own secondary machining.
Q: What alloy do you use for LED housings?
A: 6063-T5 is our standard for tube shells, linear channels and track rails. It extrudes cleanly, anodizes evenly and gives the thermal performance a passive LED fixture needs. Where a housing doubles as a structural member or must accept welding, we step up to 6061-T6. Tell us the fixture type and we will confirm the alloy with the quotation.
Q: What is the difference between an LED channel and an LED rail?
A: A channel carries the strip and a diffuser. A rail carries the whole fixture, usually on a track. They are often extruded from the same die family but sized differently, so send the section you are matching.
Q: Which alloy do you use for LED extrusion profiles?
A: 6063-T5 for most channel and rail work, 6063-T6 where stiffness over long spans matters.
Q: Can you cut LED channels to fixture length?
A: Yes, to your cutting list, with deburred ends so the diffuser slides in without snagging.

=== 2020, 2040 and 4040 Aluminum Frame Profiles ===
URL: https://www.linkedalu.com/products/industrial-aluminum/slot-aluminum-profiles/aluminum-frame-profiles-2020-2040-4040.html
Summary: 2020, 2040, 4040 and 4080 industrial aluminum profiles with practical span and load guidance, cut, drilled, tapped and labeled to your BOM so frames assemble without a saw on site.
- Profile Sizes: 2020 (20×20 mm), 2040 (20×40 mm), 4040 (40×40 mm), 4080 (40×80 mm)
- Slot Width: 5 mm on 20-series (2020, 2040); 8 mm on 40-series (4040, 4080)
- Weight per Meter: 2020 ≈0.5–0.6 kg; 2040 ≈0.9–1.2 kg; 4040 ≈1.3–1.8 kg; 4080 ≈2.5–3.5 kg
- Alloy & Temper: 6063-T5 standard; 6061-T6 on request for maximum yield strength
- Hardness: ≥15 HW
- Span Guide (loads under 50 kg): Up to 0.5 m — 2020; 0.5–1.2 m — 2040 minimum; over 1.2 m or moving parts — 4040
- Standard Length: 2.0 m; cut to length at ±0.1 mm, ends square and burr-free
- Surface Finish: Silver anodized, black anodized, or mill finish (single batch per order)
- Fabrication: CNC drilling, tapping M3–M12, part labeling, packing by assembly zone
- Quality & MOQ: Material Test Reports with every batch; MOQ 500 kg
2020, 2040, 4040 or 4080: Which Aluminum Extrusion Size? We extrude and machine four core industrial aluminum profile sizes that cover the vast majority of automation frames, workstations, enclosures and machine guards: 2020, 2040, 4040 and 4080. The numbers are cross-sectional dimensions in millimeters, so a 2020 is 20 by 20 mm and a 4080 is 40 by 80 mm. The sizing is straightforward; choosing the right profile for a given span and load is where the cost is won or lost. The Cost of Under-Sizing an Aluminum Frame Extrusion A 2020 looks perfectly adequate for a 1.2 m machine base carrying a vision system and a linear actuator. It is not. The moment of inertia is small, so at that span even the profile's own weight produces measurable sag. Add a 30 kg actuator moving back and forth and the frame sits in constant micro-motion: the camera loses its reference position, measurements drift, and the machine never reaches its accuracy specification. That is not a material defect, it is what physics says a 20 by 20 mm aluminum bar does at 1.2 m. As a rough guide for moderate loads under 50 kg, up to 0.5 m suits 2020, 0.5 to 1.2 m needs 2040 at minimum, and anything over 1.2 m or carrying moving parts calls for 4040. Mixing 20-Series and 40-Series Profiles Many frame designs mix series deliberately: 4040 legs, 2040 cross beams and 2020 stiffening braces, each chosen for a reason. The headache appears at assembly, because 20-series profiles use a 5 mm T-slot and 5 mm T-nuts while 40-series profiles use an 8 mm slot and 8 mm nuts. They are not interchangeable, and the connector joining a 4040 post to a 2040 beam has to accommodate two slot widths and two face dimensions. Transition brackets exist and work well, but they have to be planned. When a BOM includes both series we flag the mixed joints during review and pack connectors by assembly joint, each bag labeled with the two profiles it joins. 2020: Light-Duty, Short Spans At 20 by 20 mm with a 5 mm slot and a weight of roughly 0.5 to 0.6 kg per meter, 2020 is the smallest profile in common industrial use. It suits 3D printer frames, small laser engraver bodies, electronics test fixtures, bench-top enclosures, light dust covers and splash guards, cable trays and sensor rails. It does not suit any span over half a meter that bears weight, frames carrying moving actuators, or guarding someone might lean against. 2040: The Same Width, Twice the Height At 20 by 40 mm, 2040 shares its 20 mm width with 2020, so it takes the same T-nuts and connectors. The extra height gives far better bending resistance in the vertical direction, and for a horizontal beam carrying load, height does the work. Weight is roughly 0.9 to 1.2 kg per meter. Typical uses are conveyor support beams and bracket arms, mid-size inspection machine bases, workbench sub-frames and equipment mounting rails inside larger frames. 4040: The Workhorse If industrial aluminum framing had a default setting, it would be 4040 at 40 by 40 mm with an 8 mm slot and roughly 1.3 to 1.8 kg per meter. The square section gives good stiffness in both directions, and the 8 mm slot takes larger T-nuts with higher clamping force than 5 mm hardware. For spans between 1 and 2 m under typical automation loads it hits the performance-to-cost sweet spot. It is the right choice for automation machine frames, robot cell bases, inspection and test structures, heavy-duty workbenches, and guarding posts up to about 1.5 m apart. Step up to 4080 for main beams spanning more than 2 m under load. 4080: Heavy Loads, Long Spans At 40 by 80 mm, 8 mm slot and roughly 2.5 to 3.5 kg per meter, 4080 is the heavy-lifter. On a 2 m span with real load, the difference between 4040 and 4080 is the difference between visible flex and a structure that feels solid. It belongs under main beams spanning 2 to 3 m, robot mounting bases where rigidity drives positioning accuracy, AGV chassis rails and multi-level shelving columns. It is overkill for enclosure frames, guarding panels and light-duty brackets, which 4040 or 2040 handle at lower cost and weight. If your drawing shows 4080 where the load does not justify it, we will mention it during review and you make the call. Machining to Your BOM We do not ship 6 m raw bars unless you ask. Most customers send a bill of materials or an assembly drawing and we handle the rest: precision cutting to length at 0.1 mm with square, burr-free ends, CNC drilling of through, stepped and access holes, end-face tapping for hidden corner connectors and side tapping for brackets in M3 to M12, and a label on every bar matching its callout on your drawing. Profiles are packed by assembly zone so the crew opens one crate and builds that section. Surface finish options are silver anodized for most machine frames, black anodized for optical inspection equipment where reflections matter, and mill finish for internal structure. All profiles in an order are anodized in a single batch, so legs and cross beams match. Material Test Reports are provided with every batch, and the minimum order is 500 kg.
Q: We are building a 1.5 m spanning machine base carrying 200 kg. 4040 or 4080?
A: At a 1.5 m span with a 200 kg central load, 4040 shows noticeable deflection. Specify 4080 for the main load-bearing horizontal beams, and keep upright legs and secondary cross-members in 4040 to control weight and cost. Mixing sizes is normal: 4040 for the structure and 4080 only where the span or load genuinely demands it is the efficient way to design.
Q: What is the difference between 20-series and 40-series hardware?
A: Slot width, and the hardware is not interchangeable. 20-series profiles such as 2020 and 2040 use a 5 mm slot and 5 mm T-nuts. 40-series profiles such as 4040 and 4080 use an 8 mm slot and 8 mm T-nuts, which take higher clamping force. Where a frame mixes both series, transition brackets are needed, and we flag mixed joints during BOM review.
Q: Can these profiles be used in cleanroom environments?
A: Yes. Clear anodized profiles have a smooth, sealed oxide layer that does not shed particles and tolerates standard cleanroom isopropyl wiping without oxidizing. For optical inspection frames, black anodizing reduces reflections from the frame itself. For enclosed or hidden structure that will never be seen, mill finish is the lowest-cost option. We can advise on the finish that suits your cleaning protocol.
Q: Are material certificates available?
A: Yes. Material Test Reports detailing chemical composition and mechanical properties are provided with every batch. Standard structural profiles are extruded from 6063-T5, with 6061-T6 available on request where maximum yield strength is needed. Every bar is labeled to match its callout on your drawing, so a certificate can be traced back to the parts you receive.
Q: What is the difference between 2020 and 2040?
A: Same 20 mm width, twice the height. 2040 is the fix when a 2020 frame deflects under load but the assembly has to stay 20 mm wide.
Q: Can I mix 20-series and 40-series in one frame?
A: Yes, with transition plates. Mixing sizes is normal on machines where one axis carries more load than the other.
Q: How do I know which size to order?
A: Send the span, the load and the fixing points. Sizing from a deflection limit is faster and safer than guessing from a catalogue chart.

=== T-Slot and V-Slot Aluminum Extrusions ===
URL: https://www.linkedalu.com/products/industrial-aluminum/slot-aluminum-profiles/t-slot-v-slot-aluminum-extrusions.html
Summary: Custom T-slot and V-slot aluminum extrusions from 20×20 mm to 160×160 mm, with slot widths held to ±0.1 mm and straightness of 0.5 mm/m, delivered as labeled frame kits machined to your BOM.
- Alloy & Temper: 6063-T5 standard; 6061-T6 for high-load applications
- Hardness: ≥12 HW
- Cross-Section Range: 20×20 mm up to 160×160 mm; larger custom sections possible
- Slot Widths: 5 mm to 10 mm (6 mm, 8 mm and 10 mm most common)
- Slot Width Tolerance: ±0.1 mm, gauged every 50 bars with go/no-go gauges
- Cross-Section Tolerance: ±0.20 mm
- Straightness: ≤0.5 mm/m, tension-stretched to 1–3% permanent elongation
- Machined Face Flatness: Within 0.05 mm after post-extrusion CNC milling
- Fabrication: Sawing ±0.1 mm; CNC drilling; tapping M3–M12 at 6H class; end milling
- Length, Finish & MOQ: 2000 mm standard; silver or black anodizing matched to ΔE 1.0; MOQ 500 kgs
T-Slot Frame Kits, Not Random Bars T-slot aluminum extrusions in 20, 30, 40 and 45 series in 6063-T5, with slot widths held to ±0.1 mm and cut to your list from 500 kg per profile. If you have built with T-slot before you know the frustrations: a T-nut that jams halfway down the slot, a 2 m bar with a visible bow, a frame that rocks on a flat floor because one extrusion twisted during cooling. Those are not assembly errors, they are profile errors that left the factory. We extrude T-slot and V-slot aluminum profiles for industrial frames, automation guarding, workstations, linear rails and custom machine builds, and we work from your drawings rather than a catalog. Slot Widths Held to ±0.1 mm Some suppliers treat T-slot grooves as a rough feature. They are not. If the slot opening varies by 0.3 mm across a batch, a standard T-nut slides freely in one bar and needs hammering into the next, and the day disappears into sorting hardware and filing burrs. We hold slot width to ±0.1 mm on the common sizes of 6 mm, 8 mm and 10 mm. The die tongues that form the slots are cut from H13 steel with proper heat treatment and triple tempering, and every 50 bars are checked with a go/no-go gauge during production. When a tongue starts to wear, the die comes off the press for repair before bad bars leave the line. Slot walls are clean and burr-free, so a T-nut slides without binding and locks without play. Straightness, Tension Stretching and Machined Faces Extruded aluminum leaves the die hot, runs through quench and can twist or bow as it cools. If the mill does not stretch the material properly, residual stress stays locked in, and a cut 2 m piece springs into a banana. Frames built from those bars never square up, and a linear rail mounted on a bowed face follows the curve. Every T-slot and V-slot profile passes through a tension stretcher after extrusion, giving 1 to 3% permanent elongation that pulls out internal stress. We guarantee straightness at 0.5 mm per meter or better. For a surface that carries a precision guide rail, the as-extruded face may still not be flat enough, so we recommend post-extrusion CNC milling on that face, where we hold flatness within 0.05 mm. One Order, One Color A two-tone frame happens when the base profiles and the uprights are ordered separately. The first batch looks fine, and a month later the second batch arrives with a faint champagne shift that everyone notices once the frame stands in a customer lobby. We treat a frame order as one production batch: same billet heat, same anodizing tank, same cycle. Silver anodizing is the default for industrial frames because it is the most stable in color; where black is required we run it in a dedicated black tank. Before packing, all bars for the same order are checked side by side under the same light, and we keep a color reference sample so a later reorder can be matched within ΔE 1.0. What We Extrude T-slot profiles are the workhorse, with T-shaped grooves on one, two, three or four faces, designed for T-nuts that rotate 90 degrees and clamp. They are the standard for machine frames, guarding, workstations and modular structures. V-slot profiles carry V-shaped grooves with angled sidewalls, typically 45 degrees. These work directly with V-wheel bearings for linear motion, with no separate rail needed, which is why they are common in 3D printers, CNC routers, laser engravers and camera sliders. Custom mixed geometries put T-slots on three faces and a V-slot on the fourth, which suits a gantry beam that needs both frame connections and a motion axis. We extrude in 6063-T5 as standard with 6061-T6 available for high-load applications. Standard cross-sections range from 20 by 20 mm to 160 by 160 mm with slot widths of 5 mm to 10 mm, and larger custom sections are possible. Cut, Drilled, Tapped, Labeled Send a bill of materials and we handle the rest: precision sawing to 0.1 mm with square, burr-free cuts; CNC drilling of through, stepped and access holes per your drawing; end-face tapping for hidden connectors and side tapping for brackets in M3 to M12 at 6H class; and end milling for notches, steps, miter cuts and flat mounting faces. Every bar gets a label with its part number from your drawing, so the crew builds by the numbers with no saw, no drill and no guesswork on site. These profiles end up in machine frames and guarding, 3D printer and CNC router gantries, assembly benches, test and measurement fixtures, and enclosure frames with infill panels. Minimum order is 500 kgs.
Q: Can you combine T-slots and V-slots on one bar?
A: Yes. A custom die can carry T-slots on the sides for frame connections and a V-slot on the top face for a rolling axis. That keeps the gantry beam count down and simplifies assembly. V-slots have angled sidewalls, typically 45 degrees, and work with V-wheel bearings so no separate linear rail is needed. Send us the cross-section concept and we will check extrudability.
Q: How straight and flat are your profiles?
A: Straightness is 0.5 mm per meter or better out of the press, guaranteed, because every profile is tension-stretched to 1 to 3% permanent elongation after extrusion. Flatness is a separate question. For a surface carrying a precision guide rail, the as-extruded face may not be enough, so we mill that face after extrusion and hold flatness within 0.05 mm.
Q: Can you match anodized color to our existing frame?
A: If the existing frame came from us, we hold the color reference sample and match to it within Delta E 1.0. If it came from another supplier, send a physical sample and we will get as close as the die design and billet chemistry allow. For visible parts, ordering the whole frame as a single production batch is the surest way to avoid a two-tone assembly.
Q: What is the minimum order for custom T-slot profiles?
A: 500 kgs, whatever the section. A single machine frame is not too small either: we take your frame drawing or BOM, cut and machine every bar, label them and ship the kit ready to bolt together.
Q: What is the difference between T-slot and V-slot?
A: The slot profile. T-slot takes square-neck nuts and is the standard for machine frames. V-slot takes a wedge nut and is usually chosen for cleaner face geometry or where chips must not lodge.
Q: What slot tolerance do you hold?
A: ±0.1 mm on the slot, with straightness of 0.5 mm/m.
Q: Do you supply assembled frame kits?
A: Yes. Cut, drilled, tapped and labelled by position, so the frame assembles without a saw or a drill on site.

=== Solar Mounting Rails and Tracker Extrusions ===
URL: https://www.linkedalu.com/products/industrial-aluminum/solar-energy/solar-mounting-rails-tracker-extrusions.html
Summary: Aluminum solar mounting profiles: standard square and rectangular tube plus custom PV rails, C- and H-channel posts, clamp bases and BIPV gutters, supplied cut, punched and labeled as installation kits.
- Alloy & Temper: 6005A-T6 (standard structural); 6063-T5, 6005-T5, 6061-T6 and 6060-T6 also available
- Hardness: ≥15 HW
- Standard Tube Sizes: Square 40×40, 50×50, 60×60 mm; rectangular 60×40, 80×40, 100×50 mm
- Wall Thickness: 1.5 mm – 5.0 mm
- Custom Rail Sections: 35×30 mm to 68×40 mm typical; larger tracker and BIPV sections to order
- Surface Finish: Mill; anodized AA15 (15 µm) or AA20 (20 µm); PVDF 3-coat ≥35 µm; super-durable powder 60–80 µm
- Cut Tolerance: ±0.1 mm on cut-and-punched installation kits
- Press Capability: Up to 5,000 MT press force for large structural sections
- Length & Packing: 6.0 m standard; pre-cut, punched and labeled by row or assembly zone
- MOQ & Standards: 500 kg per profile on a new die; ISO 9001:2015 quality system
Custom Solar Mounting Extrusions and Standard Tube There is an ongoing conversation on solar projects about whether to use zinc-aluminum-magnesium steel or return to aluminum for certain sites. We are not here to argue that steel is wrong. We are here to make sure that when aluminum is the right call, the profiles arrive exactly as the mounting design asked, cut, punched, labeled and ready to bolt together. Some mounting systems are built entirely from standard square and rectangular aluminum tube. If that is yours, we can supply the tube. Others need a custom rail with a serrated top slot for T-bolts, a side channel for cable management, or an integrated drainage groove for BIPV. That is a custom die, and we cut those too. Steel or Aluminum? The Honest Comparison Aluminum is roughly one-third the density of steel, which on a commercial rooftop can be the difference between reinforcing the structure and not. It does not rust: the thin oxide layer that forms on bare aluminum within seconds of exposure is self-healing, so corrosion resistance does not depend on a coating staying intact. It is softer, so it cuts and drills faster and suits factory pre-fabrication over field fabrication. At end of life it remains aluminum, recyclable indefinitely, with scrap value typically 70 to 80% of the LME aluminum price. Steel still wins on large ground-mount arrays with spans over 4 m, on very high wind or snow loads where every megapascal of yield strength counts, and in regions with abundant cheap labor for on-site cutting and welding. If your project looks like that, steel is probably the economic choice and we will say so. Standard Aluminum Tubes For the structural bones of a mounting system, posts, cross beams and bracing, a standard aluminum tube or rectangular hollow section often does the job, and we keep dies for common sizes so there is no tooling charge. Square tube is available in 40×40, 50×50 and 60×60 mm, and rectangular tube in 60×40, 80×40 and 100×50 mm, with wall thickness from 1.5 mm to 5.0 mm. Alloy options are 6063-T5, 6005-T5, 6005A-T6 or 6061-T6, in mill, anodized or powder coated finish. If you need 45×45 mm or a wall thickness outside the catalog, we can usually adjust without a full new die. Custom-Extruded Profiles PV rails with integrated serrated channels and side mounting grooves. C-channel and H-channel posts with one-piece extruded base flanges and stiffening ribs. Clamp base profiles with teeth that match the rail serrations exactly. BIPV gutters and water channels with built-in slope and drip edges. Every custom profile gets a moment-of-inertia and section modulus check against the span and load data you provide. If the section looks underbuilt we say so before the die is made, and suggest a thicker web, an internal rib or an alloy step-up. Typical sections run from 35×30 mm to 40×40 mm in 6063-T6 for residential rooftop rails, 50×50 mm to 68×40 mm in 6005A-T6 for commercial and industrial racking with spans up to 1,500 mm, and custom large-scale sections in 6061-T6 or 6005A-T6 for utility tracker rails, where press capability reaches 5,000 MT. Surface Finishing for 25 Years Outdoors A solar farm is a 25-year asset, so the surface is specified for the exposure. Inland and mild climates get anodized AA15 at 15 µm with nickel salt sealing. Coastal sites over 1 km inland and high-humidity locations get AA20 at 20 µm with high-quality sealing. Coastal frontline, salt marsh and floating PV call for PVDF fluorocarbon at 35 µm or more across three coats. General outdoor work with a specific color gets super-durable powder coat at 60 to 80 µm, with 15 to 20 years expected. Before any coating, profiles go through a chrome or chrome-free conversion coating that stops filiform corrosion creeping under a coating from a scratch. Pre-Fabrication and Fasteners We offer three delivery levels: raw 6 m lengths for customers with their own fabrication shop; cut and punched, where every rail, post and beam is cut to finish length at 0.1 mm with all connection, drainage and grounding holes made per your assembly drawing; and the full kit, which adds a label on every piece matching its position on the installation drawing, packed by assembly zone or row. On coastal projects, galvanic corrosion between aluminum and dissimilar fasteners is the usual cause of pitting around bolt holes, so specify 316 stainless or Dacromet-coated fasteners with nylon washers or bushings for isolation. We can groove the bolt slot in the die to accept a nylon isolation strip. Minimum order is 500 kg per profile on a new die, while standard tube from existing dies can run at a few hundred kilos.
Q: Why choose aluminum over zinc-aluminum-magnesium steel?
A: Usually for one of three reasons: rooftop weight limits, corrosion exposure at coastal or floating sites, or installation labor cost. Aluminum is about one-third the density of steel, does not rust, and remains recyclable with scrap value typically 70 to 80% of the LME aluminum price. If none of those apply, such as a large flat ground-mount array with cheap labor, steel is often the economic choice and we will say so.
Q: Do you supply standard tube as well as custom extrusions?
A: Both. Standard square and rectangular aluminum tubes in common solar sizes come from existing dies, so there is no tooling charge and quantities can be small. Where the design needs a serrated rail, a side slot for a grounding clip, or a hollow chamber that doubles as a cable tray, that is a custom die. You will not be pushed toward one or the other.
Q: How do you confirm the rails are strong enough?
A: We check moment of inertia and section modulus against the span, panel weight and your local wind and snow loads before the die is finalized. If the section as drawn will not meet deflection limits, we suggest changes such as a thicker web, an internal rib, or a step up to 6061-T6. That conversation happens before the die is cut rather than after the first batch is installed.
Q: What causes aluminum corrosion near bolt holes on coastal jobs?
A: Galvanic corrosion between aluminum and a dissimilar fastener. Plain steel or zinc-plated bolts in salt-spray conditions make the aluminum act as a sacrificial anode, and it pits around the hole. The fix is isolation: nylon washers or bushings between bolt and aluminum, combined with 316 stainless or Dacromet-coated fasteners. We can groove the bolt slot in the die to accept a nylon isolation strip.
Q: Which alloy for solar mounting rails?
A: 6005A-T6 where the rail spans and takes wind load, 6063-T5 for shorter runs and clamps.
Q: Do you pre-drill the rails?
A: Yes, to your layout, so the modules bolt on without site drilling and the hole spacing matches the array rather than a stock pattern.
Q: What is the minimum order?
A: 500 kg per section, whether or not a new die is required.

=== Solar Panel Frame Extrusions ===
URL: https://www.linkedalu.com/products/industrial-aluminum/solar-energy/solar-panel-frame-extrusions.html
Summary: Aluminum solar panel frames extruded in 6063-T5 or 6063-T6, held to 0.5 mm/m straightness and anodized AA15 or AA20, supplied cut, CNC punched, drainage slotted and film protected for automated framing lines.
- Alloy & Temper: 6063-T5 standard; 6063-T6 or 6005-T5 for large-format and heavy snow or wind loads
- Hardness: ≥8 HW
- Straightness: ≤0.5 mm/m, tension-stretched after extrusion
- Cross-Section Dimensions: ±0.15 mm on critical features (laminate and clamp contact)
- Cut Length & Hole Position: Cut ±0.2 mm; hole position ±0.2 mm from a fixed datum
- Anodizing: AA15 (≥15 µm) standard; AA20 (≥20 µm) for coastal, floating and high humidity
- Sealing Quality: High-temperature nickel salt sealing; validated by ISO 3210 acid dissolution test
- Frame Features: Integrated grounding boss, silicone overflow groove, directional drainage slots
- Length & Fabrication: 6 m extruded; cut, CNC punched, drainage slotted, in-line PE film applied
- MOQ & Standards: 500 kg per profile shape (≈1,000 kg for a long-side/short-side pair); ISO 9001:2015
PV Frames Engineered for Automated Framing Lines A frame that twists during lamination, pits after three monsoons, or arrives at the plant with mounting holes 2 mm off is not just a defective part, it is a warranty claim waiting to happen. On the surface a solar frame looks simple: a long aluminum profile with a groove for the laminate, a slot for the mounting bolt and a few drainage paths. In an automated framing station, small deviations turn into real bottlenecks. A subtle bow can jam the framing machine, a rushed anodizing seal fails salt spray within months, and slotted holes that drift out of tolerance force installers to re-drill on site, scratching the coating and wiping out project margin. We manage the whole fabrication chain rather than just supplying the profile: precision cutting, CNC punching, drainage slotting, grounding boss integration and protective film application, so the frames arrive at your module plant ready to feed the framing machinery. Straightness: Why Micro-Twist Causes Cell Micro-Cracks If a profile has a slight structural twist, it forces the glass laminate into a constant, subtle curve while the silicone cures. That residual stress concentrates at the solar cell edges, and months later under environmental loading the micro-cracks propagate. The module may pass initial testing while its long-term power degradation curve steepens. We hold profile straightness to 0.5 mm/m or better. Every profile passes through a dedicated tension stretcher after leaving the press, because roller straightening only masks internal stress rather than removing it. Cross-sections are monitored at the start and end of every production run with a profile projector, and critical dimensions touching the laminate and mounting clamps are held to 0.15 mm. For standard rooftop projects the alloy is 6063-T5; large-format utility panels and heavy snow-load zones step up to 6063-T6 or 6005-T5. Anodizing and Sealing: Stopping White Rust White rust on anodized aluminum is almost always a sealing problem. If the oxide pores are not fully closed, moisture and salt ions penetrate the layer and cause sub-surface corrosion, which is what happens when lines use cold-sealing additives or run billets high in iron tramp elements. Our baseline for outdoor exposure is AA15 at 15 µm or more. For high humidity, coastal sites and floating solar, we mandate AA20 at 20 µm or more as an architectural finish. We seal with a high-temperature nickel salt hot-water process rather than a quick cold dip, validate every batch with the ISO 3210 acid dissolution test to confirm pore closure, and run a chrome-free passivation pre-treatment to arrest filiform corrosion at scratch points. Profiles are extruded from primary 6063 billet, never remelted scrap, because clean metal yields a clean oxide seal. Hole Position and Post-Extrusion Fabrication Misaligned tolerances stall ground-mount installations immediately. If pre-drilled frame holes miss the racking slots by a few millimeters, the crew re-drills on site, which voids the manufacturer's warranty and exposes raw aluminum to corrosion. We CNC drill or punch every mounting hole after the profile is cut to length, referencing the same datum edge across the whole batch, which keeps hole positional tolerance within 0.2 mm. Drain slots are engineered as elongated channels so water actually evacuates instead of clogging a small circular hole with dust and organic matter. Grounding marks are extruded into the die as a raised boss and pre-drilled, giving a clean flat surface for electrical contact without scraping anodizing away on site. Surface Protection in Transit Frames rejected for scratches are the most frustrating kind, because the extrusion itself may be metallurgically perfect. We apply heavy-duty PE protective film in-line as the profile exits the aging oven, and it stays on through cutting, punching and assembly. Saw and punch tooling uses nylon or rubber contact pads to eliminate metal-on-metal friction, and finished frames are stacked with foam or corrugated separators, stretch wrapped and loaded onto reinforced export pallets. The film peels cleanly at your assembly line. Profile Selection and Ordering Standard PV frames for residential and commercial modules use 6063-T5 with AA15 anodizing in silver or black. High-strength frames for large-format modules and heavy snow or wind loads use 6063-T6 or 6005-T5 with AA15 or AA20. Coastal, offshore and floating sites use 6063-T5 or T6 with AA20 and nickel sealing. BIPV, thin-film and special laminates run to specification with anodized, electrophoretic or PVDF finishes. Engineered frame features include an integrated grounding boss extruded as a raised pad, a silicone overflow groove sized to your specified adhesive bead volume, and directional drainage slots positioned so that water evacuates at varying design tilt angles. For a completely custom profile the MOQ is 500 kg per shape; because a standard frame needs both a long-side and a short-side profile, the combined entry threshold is typically 1,000 kg. Every frame in an order is extruded from one billet batch and anodized in one tank run, so color matches across every pallet.
Q: Could frame profile twist be causing our cell micro-cracks?
A: Yes, it is highly probable. If a profile bows or twists out of the press, the automated framing machine forces the glass laminate into a warped plane to close the corners. Once the structural adhesive cures, the glass is locked under continuous mechanical stress, and environmental wind or snow loads then trigger micro-cracks along the cell matrix. Holding straightness to 0.5 mm per meter or better is the control that prevents it.
Q: Is AA15 anodizing enough for a floating solar array?
A: No. AA15 and an improperly sealed layer pit quickly in high salinity and humidity. For floating solar or coastal projects within about 5 km of breaking surf we specify AA20, at 20 µm minimum, combined with high-temperature nickel salt sealing. That produces a denser barrier layer able to resist continuous chloride ion attack over a 25-year service life.
Q: Are mounting and drainage holes punched inline during extrusion?
A: No. Inline punching on the run-out table compromises tolerances, because the metal is still contracting as it cools. Profiles are first extruded, tension-stretched and fully aged to their final T5 or T6 temper, then passed to CNC fabrication where they are cut, punched and drilled from a fixed datum. That is how hole positions hold within 0.2 mm across an entire batch.
Q: What is the MOQ for a custom PV frame profile?
A: For a completely custom profile requiring new tooling, the MOQ is 500 kg per profile shape. Because a standard solar frame needs both a long-side and a short-side profile, the combined entry threshold is typically 1,000 kg to amortize engineering and die setup. If you are matching an industry-standard frame geometry we may already hold the tooling, which allows smaller validation runs.
Q: Which alloy do you use for PV module frames?
A: 6063-T5 for most module frames, with 6005A-T6 where the frame is part of the structural load path or the module is large.
Q: Do you punch the corner key holes?
A: Yes, to your module drawing, so the frame assembles with the corner keys you already use rather than a proprietary joint.
Q: What is the minimum order?
A: 500 kg per section. A module programme usually needs four sections and they consolidate into one shipment.

=== Tent and Marquee Frame Profiles ===
URL: https://www.linkedalu.com/products/industrial-aluminum/tent-aluminum-profiles/tent-marquee-frame-profiles.html
Summary: Custom aluminum tent poles, marquee beams and folding frame profiles in 6061-T6 and 6063-T5, CNC drilled from a single datum and finished with outdoor-grade coatings, shipped as labeled site-ready kits.
- Alloy & Temper: 6061-T6 for clear spans over 6 m; 6063-T5 for pop-up and telescopic sections
- Yield Strength: 6061-T6 ≈240 MPa vs 6063-T5 ≈160 MPa (about 50% higher)
- Hardness: ≥11.5 HW
- Cut Length: ±0.15 mm
- Hole Position: ±0.15 mm, CNC drilled from one absolute datum
- Pin Hole Diameter: H8 reamed tolerance; stainless or nylon bushings pressed on request
- Profile Straightness: ≤0.5 mm/m
- Surface Finish: Super-durable polyester powder (1000+ h xenon arc), PVDF fluorocarbon, anodized 15–25 µm, wood-grain sublimation
- Pretreatment: Multi-stage chrome-free conversion coating to prevent filiform corrosion
- Length, MOQ & Packing: 6 m standard; MOQ 500 kg; labeled site-ready assembly kits
The Structural Skeleton Inside Modern Shelters Folding frame and tent aluminium extrusions — marquee beams, purlins, eave and leg sections — are run in 6063-T6 and cut to your frame drawing, so the joints close without site adjustment. 500 kg per profile, whether or not a new die is cut. If tent beams bend after one windy season, bolt holes will not line up without a file on site, or a bright powder coat fades to chalky pink by August, those are not tent problems. They are extrusion supplier problems. We manufacture the aluminum structural skeleton inside modern shelters: round tubes for heavy-duty pop-up canopies, rectangular beams for clear-span event marquees, oval poles for folding festival tents, and custom engineered profiles with integrated hinge bosses, sliding tracks and locking channels for military and rapid-deployment relief shelters. Tent aluminum is not passive architectural cladding. It is erected and torn down repeatedly, packed into trailers and dragged across fields, baked in direct UV for months, and loaded by dynamic wind that yanks on every bolted joint. The profiles must be straight, strong and punched with precision, because when a two-person crew assembles a 10 m marquee in a remote field they do not have a drill press. Beams and Poles: 6061-T6 for Clear Spans Over 6 m For any clear-span marquee exceeding 6 m, or any temporary structure engineered for year-round snow loads, we default to 6061-T6. Its yield strength is approximately 240 MPa against roughly 160 MPa for 6063-T5, an increase of about 50%, which dramatically reduces elastic deflection for a given beam depth. It also lets a design engineer specify a slimmer, lower-profile beam while holding the required stiffness, saving transport weight and freight cost. Before cutting dies or extruding billets, our engineering team verifies the profile's section modulus and second moment of area against the target span, local wind loading codes and regional snow specifications. If the safety factor looks marginal we suggest targeted changes before tooling up: localized wall thickening at high-stress bending zones, internal structural webbing to prevent cross-sectional buckling, or an alloy upgrade from 6063-T5 to 6061-T6. Bolt Holes Drilled From a Single Datum A marquee side-wall frame can carry dozens of bolt holes that must register perfectly with matching connectors. Hand-drilled or jig-marked holes drift, and field crews end up enlarging holes with round files or cordless drills, which creates sloppy joints, makes the frame rattle in wind, and accelerates bolt shear wear. We CNC drill every mounting hole from a single absolute reference datum across the profile. Cut length is held to 0.15 mm so the frame squares up and the fabric roof fits snugly; hole position is held to 0.15 mm so bolts slide through without reaming; straightness is 0.5 mm/m or better so long roof beams do not bow; and pin holes are reamed to H8 tolerance for a precise pivot fit without slop. If you use standard cast aluminum nodes or stamped steel connectors, we can match-drill test samples to guarantee the fit. Every component is laser-engraved or inkjet labeled with its part number and alignment index marks. Hinges and Pivot Points That Do Not Wallow Out Folding canopies, pop-up tents and scissor-frame shelters rely on mechanical pivots, where stainless bolts or clevis pins run directly through aluminum walls. Over a busy event season the softer aluminum hole can wallow into an oval and the frame loses rigidity. We solve pivot wear at the design stage in three ways. Wall thickening is added only around the hinge boss zone instead of weight across the whole profile. Pin holes are reamed to H8 precision so the bore is mirror smooth rather than ridged, which cuts initial mechanical wear. For heavy-duty commercial hire stock or military shelters we factory-press stainless steel or self-lubricating nylon bushings into the reamed holes, so the pin rides on hardened steel or low-friction nylon rather than on the aluminum parent metal. Coatings for High-UV Outdoor Exposure Tent frames sit in high-UV environments for weeks at a time, and interior-grade polyester powder breaks down quickly, chalking white residue onto hands and fabric while brand colors fade. We specify architectural-grade systems: super-durable polyester powder for commercial marquees, rental pop-ups and festival structures, passing 1000+ hours of xenon arc testing with 10 to 15 years expected outdoors; PVDF fluorocarbon in two or three coats for permanent resort pavilions, glamping domes and coastal structures, at 20 years or more with maximum color stability; wood-grain sublimation with a topcoat for eco-lodges and pergolas; and anodizing at 15 to 25 µm for clean industrial shelters, expedition poles and sliding tracks. Before powder application every profile undergoes a multi-stage chrome-free conversion coating, which stops the creeping filiform corrosion that spreads beneath paint from a field scratch. Supply by Tent Type and Ordering Clear-span event marquees get large multi-channel rectangular main beams such as 120×68 mm and 200×120 mm with round eave columns and base plates, supplied in 6061-T6 and pre-drilled with keder fabric slots. Commercial pop-up canopies use hexagonal or square leg profiles at 40 mm and 50 mm plus scissor truss bars in thin-wall 6063-T5 with tight tolerances for smooth telescopic sliding. Rapid-relief and military shelters use heavy-wall round tubes and reinforced connector nodes in high-strength 6061-T6 with ultra-durable coatings. Glamping domes and eco-resorts use architectural oval profiles and curved structural ribs. Standard length is 6 m, minimum order is 500 kg, and profiles ship as labeled, site-ready assembly kits.
Q: Can you guarantee clear-span marquee beams for year-round high-wind sites?
A: We review the cross-section against your target span, wind loads such as up to 100 km/h, and regional snow loads. If a standard 6063-T5 profile would deflect excessively, we recommend upgrading to 6061-T6, increasing wall thickness at high-stress points, or deepening the section. Section modulus and second moment of area are checked before any dies are cut.
Q: Can you make telescopic tent legs that slide smoothly?
A: Yes. We hold tight dimensional tolerances on both the inner and outer profiles so the sliding fit is smooth without excess rattle or binding. We can also integrate dedicated nylon glide inserts into the profile channel to remove metal-on-metal friction and prevent scratch marks. Send the leg diameters and the telescopic travel you need, and the fit clearance is set at the tooling stage.
Q: What stops hinge pin holes wearing oval?
A: Three things. Wall thickening is localized around the hinge boss instead of adding weight across the whole profile. Pin holes are reamed to H8 tolerance so the bore surface is smooth rather than ridged. And for rental or heavy-use frames we factory-press stainless steel or self-lubricating nylon bushings, so the pin rides on the bushing rather than on the aluminum parent metal.
Q: Do you help with new shelter designs that have no final CAD yet?
A: Yes. Send a preliminary sketch, key target dimensions, expected load requirements and how you intend to connect the frame nodes. Our structural design engineers will draft a production-ready aluminum extrusion profile, recommend the correct alloy and temper, and optimize the cross-section for cost-effective manufacturing at no extra design charge.
Q: What sets the section for a marquee span?
A: The span and the snow or wind load, not the tent size on the catalogue. Send the span and the load case and we size the rafter section from it.
Q: Do you supply rafters, legs and eaves as a set?
A: Yes, cut to your cutting list, so the frame assembles by position without site cutting.
Q: What is the minimum order?
A: 500 kg per section, whether or not a new die is required.

=== Roof Rack and Tent Frame Extrusions ===
URL: https://www.linkedalu.com/products/industrial-aluminum/transportation-aluminum-profiles/roof-rack-tent-frame-extrusions.html
Summary: Custom aluminum extrusions for automotive roof racks and outdoor camping systems: crossbars, side rails, foot bases, tent poles and hinge bodies, with outdoor-grade anodized, powder coated or PVDF finishes.
- Alloy & Temper: 6061-T6 and 6063-T6 for structural parts; 6063-T5 for telescopic and hinge sections
- Additional Alloy: 7005-T6 for tent frame poles
- Hardness: ≥15 HW
- Surface Finish: AA15 or AA20 anodized with high-temperature nickel salt sealing; super-durable polyester powder (1000+ h xenon arc); PVDF fluorocarbon; electrophoretic coating
- Hole Position Tolerance: ±0.15 mm, CNC drilled from a single datum per part
- Profile Straightness: ≤0.5 mm/m, tension straightened after extrusion
- Telescopic Fit: CNC-machined sliding surfaces to a controlled clearance (e.g. 0.15 mm diametral)
- Pin Holes: H8 reamed; stainless steel or nylon bushings pressed on request
- Bending: Rotary-draw and roll bending to specified radius
- Length & MOQ: 6.0 m extruded; MOQ 500 kg on a new die, 200 kg from an existing die
Extruded to Your Drawings for Outdoor Duty Your crossbars sit under direct UV 365 days a year. Your tent frames get folded, rained on, yanked and shoved back into gear bags. When an anodized coating fades, a sliding mechanism jams, or a mounting hole misses by a millimeter, the end customer blames the brand, but the failure usually started at the extrusion press. We extrude, machine and finish custom aluminum profiles engineered for automotive roof racks and outdoor camping systems. You supply CAD drawings or physical samples; we build the die, execute post-extrusion CNC machining, apply outdoor-grade surface treatments and ship finished components. We do not push close-enough standard catalog shapes. Sun: UV-Stable Finishes, Not Dyed Black Anodizing A roof rack crossbar in direct summer sun can reach 70 to 80 °C at the surface, and the UV exposure never stops. Organic dyes and cheap resins break down under that punishment: dyed black anodized profiles look sharp out of the box and turn reddish then grayish after two or three years, while a wrong powder chalks and loses gloss until a finger drawn across it comes away white. We do not use indoor-grade powder on outdoor parts. For roof racks and tent frames we use super-durable polyester powder rated for 1000+ hours of xenon arc weathering, or PVDF fluorocarbon if the rack is permanently mounted and the owner expects it to look the same in year ten as on day one. For anodized finishes we go to AA15 or AA20 thickness rather than AA10, and seal with high-temperature nickel salt rather than a quick cold dip, because sealing is what stops the oxide pores absorbing moisture and contaminants. Rain and Standing Water: Drainage Designed Into the Die Rainwater itself is not the enemy; what it leaves behind is. Water pools in T-slot channels, inside tube ends and around bolt holes, dries, pools again, and each cycle deposits a trace of whatever was dissolved in it, including road salt, dust and pollution. Over months those traces concentrate and attack the anodized layer from inside the pores. For profiles with closed cavities or upward-facing channels we can incorporate drainage slots or weep holes at the extrusion stage, positioned where water naturally collects. If your drawing already includes them we machine them precisely. If it does not and we spot a water trap, we flag it during die review and you decide whether to add drainage. Thermal Cycling and Pretreatment A 1.5 m roof rack crossbar expands by about 2 mm between a cold morning and a hot afternoon. The aluminum moves and the coating has to move with it. Anodizing is part of the aluminum and expands at the same rate, so it does not crack. Powder coating and PVDF rely on adhesion: if pretreatment was done properly the coating stretches with the metal, and if it was skipped or rushed the bond fails at the interface after enough cycles and the coating lifts in sheets. Pretreatment, whether chrome or chrome-free passivation before anodizing or powder coating, is where we do not cut corners. It costs a few cents per kilo and time in the line, and it stops filiform corrosion, the thin white worms that creep under a coating from a tiny scratch. Tolerance Problems Behind "Cheap-Feeling" Racks Read enough owner reviews and the same complaints repeat, and they are manufacturing problems rather than design problems. A crossbar adjuster that needs kicking into position. A telescopic or sliding mechanism needs a controlled gap between inner and outer profiles. You cannot hit a consistent 0.2 mm clearance if tube dimensions wander by 0.3 mm across a batch, so we CNC machine the sliding surfaces after extrusion and hold the clearance your drawing specifies. If it does not specify, we ask. Mounting holes that do not line up. We drill every hole on a CNC machining center from a single datum per part, with position tolerance of 0.15 mm across the batch. For a system where crossbar, rail and foot bracket must bolt together, all parts are machined in the same production window using the same reference setup, and we spot-check assembly before packing. Crossbars that are not parallel. A crossbar that left the plant with a 3 mm bow never mounts flat. We tension-straighten every profile after extrusion and hold straightness to 0.5 mm per meter or better. Where the drawing specifies a designed arc for aerodynamic or load reasons, we straighten to that arc rather than to a flat line. What We Make and How We Finish It Roof rack crossbars are typically aerodynamic oval, rectangular or T-slot top sections in 6061-T6 or 6063-T6. Roof rails and side rails are curved or straight profiles, raised or flush mount. T-slot mounting tracks for accessory attachment run in 6063-T5. Foot bases and clamps are shaped blocks and clamping jaws in 6061-T6. Tent frame poles are round, oval or rectangular tubes in 6063-T5 or 7005-T6, telescopic pole sets pair an inner and outer tube with machined locking collars, and hinge extrusions form pivot bodies and folding joints. Finishes include AA15 anodized with nickel sealing for roof rails and metallic-look tent poles, AA20 for premium racks and marine tent frames, super-durable polyester powder in full RAL colors for colored crossbars and tent frames, PVDF fluorocarbon for permanently mounted racks and overlanding systems, and electrophoretic coating for hidden structural parts and internal tubes. All finishing is done in-house, and every profile for one order passes through the same tank or booth on the same shift, so roof rails match crossbars and foot covers. We also rotary-draw and roll-bend tubes to your specified radius, ream pin holes to H8 tolerance and press stainless bushings where wear matters, and ship pre-machined parts cut, drilled, tapped and labeled so your team bolts or pins the assembly together. Minimum order is 500 kg on a new die, or 200 kg from an existing die.
Q: Why do some telescopic crossbars slide smoothly while others bind or rattle?
A: Because the gap between the inner and outer profiles is not being controlled in production. Extruded surfaces without post-machining can vary enough across a batch to cause exactly that. We CNC machine the sliding surfaces after extrusion, so a specified 0.15 mm diametral gap is held across the batch and every unit takes the same hand-adjustment force.
Q: How do we keep black roof rails from turning gray?
A: Conventional black anodizing uses organic dye that UV destroys, so the color goes reddish, then gray, then patchy while the aluminum underneath stays sound. For black that stays black, use super-durable polyester powder coat in matte or satin black. If the design needs the metallic depth of anodizing, specify electrolytically colored anodizing, where the color comes from metal ions in the oxide pores rather than dye.
Q: Can all the aluminum parts of one rooftop tent be the same color?
A: Yes. We extrude every profile for one tent system from the same billet batch, then anodize or powder coat them together in a single production run. Tubes, hinge bodies and mounting brackets all pass through the same tank or booth at the same time, so the frame arrives in one consistent color instead of a set of near-matches.
Q: Do you supply pre-machined parts that are ready to assemble?
A: That is how most customers in these industries order. Send your BOM or assembly drawing. We cut every profile to length, drill the holes, ream the pin bores, tap the threads, bend tubes where required, and label each piece. The pallet arrives and your team bolts or pins it together, with no saw, no drill press and no scrap on the shop floor.
Q: Do you supply the crossbars and side rails together?
A: Yes. They normally run as one die family so the end caps and the mounting slots line up without rework at assembly.
Q: Which alloy for roof rack bars?
A: 6063-T6 for most crossbars, since stiffness over the span matters more than the finish.
Q: What is the minimum order?
A: 500 kg per section, whether or not a new die is required.

=== Aluminum Angle Profiles ===
URL: https://www.linkedalu.com/products/standard-aluminum/angle-aluminum-profiles/aluminum-angle-profiles.html
Summary: Extruded aluminum L-angle in equal and unequal leg, supplied in 6063-T5 and 6061-T6 for framing, bracing, brackets and corner reinforcement. Cut, drilled, tapped, welded and finished to your drawing.
- Alloy & Temper: 6063-T5 standard; 6060-T5 and 6061-T6 on request
- Profile Type: Extruded L-angle, equal leg and unequal leg
- Standard Sizes: 20 x 20 to 100 x 100 mm equal leg; 50 x 25 to 100 x 50 mm unequal leg
- Wall Thickness: 2.0 mm to 10.0 mm
- Mechanical Properties: 6063-T5: Rm 160 MPa / Rp0.2 110 MPa min.; 6061-T6: Rm 260 MPa / Rp0.2 240 MPa min.
- Hardness: 8 HW min. (6063-T5)
- Standard Length: 6.0 m mill length, cut to your call-up list
- Cutting & Machining Tolerance: +/-0.5 mm cut length up to 3 m; +/-0.2 mm CNC hole position; 6H threads
- Surface Finish: Mill finish, anodized AA10/AA15/AA20, powder coated 60 um+, PVDF
- Standards: GB/T 5237, EN 755-9, ASTM B221; MTC to EN 10204 3.1
Why Aluminum Angle Profiles Are the Most-Used in Fabrication Ask any fabricator which extrusion comes off the rack most often and the answer is the same: aluminum angle. Two legs meeting at 90 degrees resist bending in two directions at once in a section that weighs roughly a third of the equivalent steel angle. It braces, frames, trims, reinforces and mounts. Linkedalu Metal Group Co., Ltd extrudes custom aluminum angle in equal-leg and unequal-leg configurations for framing, bracing, corner reinforcement, shelving and structural brackets, with mill test certificates issued to GB/T 5237, EN 755-9 or ASTM B221. Because the section is extruded rather than press-braked from sheet, the cross-section repeats from one end of the bar to the other, the inside corner is consistent and the wall thickness is uniform. That repeatability is what allows a mating component to fit and a load path to be predicted. Equal Leg vs Unequal Leg Aluminum Angle: Choose by Load Path Equal leg (a/b = 1.0) — 25 x 25, 50 x 50 and 100 x 100 mm are the default workhorses. Both legs share the structural duty, so a load can arrive from either direction. Specify equal leg for enclosure corner reinforcement, square machine-base framing, shelf supports and architectural trim where visual symmetry matters. Unequal leg — 50 x 25, 75 x 50 and 100 x 50 mm pair a longer leg for fastening or stiffness with a shorter leg that keeps the profile compact. Typical uses are wall-mounted shelf brackets, ledge and awning supports, panel edge framing and asymmetric connections where the load is heavier in one direction. Choosing wrongly usually shows up as wasted material or a poor fit. When in doubt, equal leg for balanced duty and unequal leg for one-sided mounting. Alloy and Temper: 6063-T5, 6060-T5 and 6061-T6 Property 6063-T5 6060-T5 6061-T6 Tensile strength Rm 160 MPa min. 160 MPa min. 260 MPa min. Yield strength Rp0.2 110 MPa min. 120 MPa min. 240 MPa min. Elongation A50 8 % min. 8 % min. 8 % min. Anodized appearance Bright and even Bright and even Slightly grayish Weldability Acceptable, light duty Acceptable, light duty Excellent These are minimum thresholds from GB/T 5237.1 and EN 755-2; the figures that apply to your order are the measured values on the mill test certificate. 6061-T6 has roughly twice the yield strength of 6063-T5, which makes it the safer choice for machine bases, welded frames, roof-rack crossbars and any angle that carries real load. 6063-T5 extrudes more cleanly and anodizes more uniformly, so it is the right answer when the angle is visible and the duty is light. Buckling, Slenderness and the b/t Rule On a 100 x 50 mm unequal-leg angle under compression, the long leg is stiffer because it carries more material while the short leg is more slender and therefore more prone to local buckling. The section does not fail uniformly; it fails where slenderness is highest. For compression-loaded angles, prefer equal leg where the geometry allows. Where unequal leg is required, size the short leg so its width-to-thickness ratio stays at or below about 12, or move up from 6063-T5 to 6061-T6 so the section can develop its yield capacity before elastic buckling begins. Yield strength alone is not a sufficient check on a thin-wall unequal angle. Reference Weights for Equal-Leg Angle Leg x Leg (mm) Wall t (mm) Weight (kg/m) 25 x 25 2.0 0.26 40 x 40 3.0 0.62 50 x 50 3.0 0.78 60 x 60 5.0 1.54 100 x 100 6.0 3.11 100 x 100 10.0 5.08 Values are theoretical kilograms per meter and reference only. Actual mill weight varies with tolerance and corner radius, so the certified weight travels on the mill test certificate. Where Aluminum Angle Replaces Steel Angle Aluminum weighs roughly 35 percent of steel by volume, so an equal-strength bracket ships and installs lighter and imposes less load on the structure it bolts to. Aluminum angle also survives humid, marine and mildly chemical environments without rusting, and it cuts, drills, taps and machines with standard tooling. Steel still wins on raw load capacity per unit cost, so for a heavy stationary machine base or a structural column where weight is not a constraint, steel remains the economical choice. The case for aluminum is the problem it solves rather than the strength it claims. Cut, Drill, Tap, Weld and Finish Standard mill length is 6.0 m. We cut to your call-up list with a length tolerance of plus or minus 0.5 mm on pieces up to 3 m and plus or minus 1.0 mm on longer mill lengths, and programmable miter saws handle angled ends and notches. CNC drilling holds hole position to plus or minus 0.2 mm, and tapped holes such as M5, M6, M8 and M10 are produced to a 6H fit. Where an assembly depends on matched holes, mating parts are drilled and tapped in the same setup so they index correctly on site. 6061-T6 welds excellently with TIG or MIG using 4043 or 5356 filler; the heat-affected zone loses some temper, so welded 6061 angles are specified as 6061-T6 base with the weld zone allowance built into the design. 6063-T5 can be welded but is normally chosen for non-welded assemblies. Finish options run from standard mill finish through anodizing at Class AA10, AA15 or AA20 for marine and visible architectural work, architectural-grade powder coating at 60 micrometers and above, and PVDF for high-UV or coastal exposure. How an Angle Order Moves Through the Mill You send the drawing: leg lengths, wall thickness, alloy, temper, finish and fabrication list. We confirm extrudability and return theoretical weight per meter and per piece, flagging geometry that will not extrude cleanly. New die or reused die, locked to a single billet batch. Extrusion, straightening, cut-to-length, CNC drilling, tapping or notching, then finishing and labeling. A mill test certificate to EN 10204 3.1 is issued against GB/T 5237, EN 755-9 or ASTM B221. Minimum order quantity is 500 kg for a new die, with smaller trial quantities reviewed against our existing die library. Bars are supplied shrink-wrapped and labeled to your call-up list.
Q: Should I use 6061-T6 or 6063-T5 for an aluminum angle bracket?
A: It depends whether the bracket is structural or decorative. 6061-T6 has roughly twice the yield strength of 6063-T5, at 240 MPa against 110 MPa, welds cleanly and is the safer choice for machine bases, welded frames, roof racks and structural brackets. 6063-T5 extrudes more cleanly, anodizes more uniformly and produces a brighter, more even surface, so choose it when the angle is visible and is not carrying structural load.
Q: Does an unequal leg angle buckle at the short leg?
A: Usually, yes. The longer leg is stiffer because it carries more material, while the shorter leg has a larger width-to-thickness ratio and is more susceptible to local buckling. Under compression the section fails where slenderness is highest, typically the short leg buckling first in the elastic range. Keep b/t at or below about 12 for typical aluminum angle, or upgrade from 6063-T5 to 6061-T6 so the section can develop its yield capacity before elastic buckling starts.
Q: How much does aluminum angle weigh per meter?
A: It depends on leg length and wall thickness. A 50 x 50 x 3 mm equal-leg angle weighs roughly 0.78 kg/m, a 60 x 60 x 5 mm section about 1.54 kg/m, and a 100 x 100 x 10 mm angle about 5.08 kg/m. Those figures are theoretical; actual mill weight varies with dimensional tolerance and corner radius, and the certified weight for your batch is stated on the mill test certificate.
Q: Can 6063-T5 aluminum angle be welded?
A: Yes, with caveats. 6063-T5 has good weldability for non-structural assemblies, but the heat-affected zone loses temper and the weld zone ends up at roughly T4 strength. For welded light-duty frames we normally recommend 6061-T6 instead, because it welds more cleanly, holds post-weld strength better and gives the design engineer a more predictable strength figure to calculate with.
Q: Do you supply unequal leg aluminum angle?
A: Yes, in any leg combination you specify. Unequal leg angle is used where one flange carries the load and the other only stiffens, and we extrude it to your leg lengths rather than trimming a stock equal-leg section.
Q: What leg lengths and thicknesses can you extrude?
A: From 0.8 mm wall, with leg lengths set by your drawing. Send the section; if it fits a 540 mm circumscribed circle it runs on our presses.
Q: What is the minimum order for aluminum angle?
A: 500 kg per section, whether or not a new die is required.

=== Aluminum Rectangular Tubes ===
URL: https://www.linkedalu.com/products/standard-aluminum/rectangular-tubes/aluminum-rectangular-tubes.html
Summary: Factory-direct extruded aluminum rectangular tubes and flat pipes in 6063 and 6061 alloys, with tailored wall thicknesses, internal reinforcement ribs, CNC fabrication and architectural finishes.
- Alloy & Temper: 6063-T5, 6063-T6, 6061-T6, 6005-T5
- Profile Type: Extruded rectangular hollow section (flat pipe), single-piece, seamless
- Size Range: 10 x 10 mm to 200 x 100 mm outside section
- Wall Thickness: 0.8 mm to 10.0 mm, asymmetric walls on request
- Internal Features: Integral ribs, webs, dividers and screw ports formed in the extrusion pass
- Hardness: 14 +/- 2 HW
- Standard Length: 6,000 mm production bars; 7,000 mm on request; fixed cuts 100 mm to 6,000 mm
- Surface Finish: Anodizing 10-25 um, powder coating 60-100 um, electrophoresis, mill finish
- CNC Fabrication: Miter sawing within +/-0.1 mm, multi-axis drilling, tapping M3 to M16, stretch bending
- Standards: GB/T 5237, EN 755-9, ASTM B221; mill test certificate with heat number
What Custom Extrusion Buys You Over Catalog Tube Rectangular tube from 10 × 10 mm to 200 × 100 mm outside section, walls from 0.8 mm to 10.0 mm, extruded in 6063-T5/T6, 6061-T6 or 6005-T5 and supplied in 6,000 mm bars or fixed cuts from 100 mm. 500 kg per profile. Catalog tube forces a compromise. When a standard wall thickness falls just short of a load-bearing point, the usual answer is to jump to the next stock size, which adds dead weight, raises material cost and grows the footprint of the assembly. A dedicated die removes that compromise. Linkedalu Metal Group Co., Ltd produces custom-extruded aluminum rectangular tubes, also called flat pipes or rectangular hollow sections, so the cross-section can be optimized to the job rather than to a stock list. Extruded hollow sections are formed as one continuous piece of metal rather than rolled and welded from strip. There is no longitudinal weld to act as a weak zone, which improves fatigue behavior under vibration and keeps the visible face uniform through anodizing or powder coating. Tailored Wall Thickness and Internal Ribs Two design freedoms are worth more than any other on a rectangular tube: Asymmetric wall thickness. Material can be concentrated on the faces that carry the load while non-structural faces stay thin. A shallow channel section can be thickened under a bolted joint and left light everywhere else. Integral ribs and webs. Internal dividers, bulkheads and screw ports are formed in the same extrusion pass. A single internal rib can raise a rectangular tube's moment of inertia and torsional resistance by more than 30 percent without changing the outside dimensions. Multi-hollow sections with internal ribs and structural bulkheads are a routine production item rather than a special, and they are the most efficient way to stiffen a machine frame without inflating it. Choosing the Alloy: 6063-T5, 6063-T6, 6061-T6 and 6005-T5 6063-T5 is the most economical and the most extrudable of the group. It forms complex geometry and thin walls with a smooth surface that takes anodizing and powder coating beautifully, which suits architectural trim, enclosures and light-duty framing. 6063-T6 applies solution heat treatment and artificial aging to the same alloy and lifts its yield strength by roughly 30 percent while keeping the crisp surface, making it suitable for medium-load outdoor frames and glazed support work. 6061-T6 is the structural workhorse. Its tensile and yield thresholds rival low-carbon mild steel, it welds and machines well, and it is the industry standard for heavy machinery frames, automation sub-bases and transport chassis. 6005-T5 sits between the two: stronger than 6063 and more extrudable than 6061, with very little deformation during cooling, which is why it dominates heavy-duty structural beams, solar mounting and rail transit components. Surface Engineering for Indoor and Outdoor Service Architectural anodizing at 10 to 25 micrometers converts the surface into a hard aluminum oxide layer in silver, champagne, bronze or black, improving wear resistance and holding a metallic appearance. Industrial powder coating at 60 to 100 micrometers provides a thick barrier against impact, chemicals and ultraviolet radiation for a service life measured in more than a decade in commercial settings. Electrophoresis is the answer for hollow sections in high-humidity or marine conditions, because the paint layer reaches the inner walls as well as the outside faces. Anodizing solution flows through the full internal cavity, so inner surfaces are coated too, though very long or narrow tubes can see a slightly thinner coating near the center. Corner Radii and Internal Cavities Internal corners are designed with a fillet radius equal to or greater than the wall thickness. Those rounded corners avoid stress concentration and extend die life. Where a drawing calls for a strictly sharp internal corner, the geometry is reviewed at the design stage before tooling is cut. Fixed-length cuts are available from 100 mm to 6,000 mm, and standard production bars run 6,000 mm with 7,000 mm possible on request. From Extrusion to Bolt-Ready Parts Extrusion and secondary machining happen under one roof, which shortens the route from billet to assembly line and removes the handling damage caused by shipping raw profiles between vendors. Precision miter sawing holds lengths within plus or minus 0.1 mm, multi-axis CNC drilling produces accurate hole patterns, threads are cut from M3 to M16, and stretch bending forms curved sections where the design requires them. The result is a hollow section that arrives pre-cut, deburred and ready to bolt into the machine rather than a raw bar that still needs sawing, scrap disposal and labor on site. Size Range, Tolerances and Documentation Standard tooling covers cross-sections from a compact 10 x 10 mm to a large 200 x 100 mm, with larger sizes evaluated on request. Wall thickness runs from 0.8 mm for lightweight trim to 10 mm for heavy structural duty. Hardness is typically 14 plus or minus 2 HW. Unless a project specifies otherwise, dimensions and tolerances follow GB/T 5237, EN 755-9 or ASTM B221 as agreed at order review. Every shipment carries a mill test certificate with heat number, chemical composition and mechanical results, and third-party inspection by SGS or Intertek can be arranged before dispatch. Tubes are wrapped individually, bundled with steel strapping, protected with waterproof film and packed into pallets or wooden crates for ocean freight. Minimum order quantity is 500 kg for a new die; straightforward sections that already exist in our die library can be discussed at smaller trial volumes. Applications Custom rectangular tube is specified for machine frames and equipment bases, conveyor and gantry structures, solar mounting rails, trailer and vehicle frames, exhibition and display systems, curtain wall support members and any framework where the tall axis has to carry bending while the assembly stays light. Send a drawing or a sketch with the target wall thicknesses marked clearly. Our engineers review it and confirm feasibility, theoretical weight and the recommended alloy before the die is cut.
Q: Why choose an aluminum rectangular tube over stainless steel square tubing?
A: Weight is the biggest difference: aluminum is around 65 percent lighter, which makes handling, shipping and installation cheaper. Aluminum also resists corrosion naturally without the chloride pitting that stainless steel can suffer in some environments. Anodizing or powder coating opens up a wide choice of colors and finishes, where steel is normally limited to raw metal or paint. Added together with a low-maintenance service life, aluminum usually carries the lower total cost of ownership.
Q: What are the largest and smallest sections you can extrude?
A: Standard tooling covers cross-sections from about 10 x 10 mm up to 200 x 100 mm, and larger sizes can be evaluated on request. Wall thickness ranges from 0.8 mm for lightweight trim up to 10 mm for heavy structural loading. Send your blueprints and our engineers will verify manufacturability for the size, wall combination and alloy before quoting.
Q: Can you produce a rectangular tube with uneven wall thicknesses?
A: Yes. Distributing metal to the faces that do the work is one of the main advantages of custom extrusion over stock tubing. You can thicken the primary load-bearing wall, leave the cosmetic or non-structural faces thin, and reduce overall weight without downgrading the section. Just mark the target wall thickness clearly on the drawing for each face, because the extrusion die is cut to those individual wall call-outs.
Q: Will the inside walls be anodized on a hollow rectangular tube?
A: Yes. Anodizing solution flows through the full internal cavity and forms a protective oxide layer on the inside surfaces as well as the outside faces. On exceptionally long or narrow tubes, restricted flow can leave the internal coating slightly thinner near the center of the bar. If you have a strict micron requirement for inner walls, tell us at the quotation stage so the process parameters can be adjusted.
Q: Sharp corners or radiused — can you do both?
A: Yes. Sharp corners are a die decision rather than a rolling limit, so the corner radius follows your drawing instead of a stock range.
Q: What wall thickness can you run?
A: From 0.8 mm, with the practical upper limit set by the section and the alloy rather than a fixed number.
Q: What is the minimum order?
A: 500 kg per section, whether or not a new die is required.

=== Aluminum Round Tube and Pipe ===
URL: https://www.linkedalu.com/products/standard-aluminum/round-tubes/aluminum-round-tube-and-pipe.html
Summary: Extruded aluminum round tube for structural framing, handrails, marine hardware, heat exchangers and hydraulic lines, supplied in seamless, welded or drawn-over-mandrel form with mill test certificates.
- Alloy & Temper: 6061-T6, 6063-T5, 7075-T6, 5052-O, 3003-O
- Manufacturing Route: Seamless extruded, welded (ERW), or drawn-over-mandrel (DOM)
- Tube vs Pipe Standards: Tube: ASTM B210 / B221 / B345. Pipe: ASTM B241 / B429
- Outside Diameter Tolerance: +/-0.10 mm to +/-0.25 mm depending on size
- Wall Thickness Tolerance: +/-10 % of nominal
- Roundness / Ovality: 1 % of outside diameter or better
- Straightness: 0.8 mm per 1,000 mm or better
- Cut Length Tolerance: +/-1 to +/-5 mm standard cut; +/-0.1 to +/-0.5 mm precision cut
- Concentricity: Seamless approx. 5 % wall variation; DOM approx. 2 %
- Surface Finish: Mill finish, anodized AA10/AA15/AA20, powder coated 60 um+, PVDF
Tube or Pipe? Specify the Right Product First Seamless extruded aluminium tube and pipe in 6063 and 6061, from 12 to 200 mm outside diameter, cut to your length list and finished in-house. 500 kg per profile, whether or not a new die is needed. Both words describe a hollow cylinder, and confusing them costs a project weeks of fittings that will not seat. A tube is specified by its exact outside diameter and wall thickness, and its standards are ASTM B210, B221 and B345 for extruded tube. A pipe is specified by nominal pipe size and schedule, under ASTM B241 or B429, and it carries fluid and gas. Point Tube Pipe Specified by Exact OD plus wall thickness Nominal pipe size plus schedule Tolerance Tighter, typically 10 percent on wall Schedule based, looser on bore Shape Round, square, rectangular, oval, custom Round only Primary use Structural, heat exchangers, precision frames, handrails Fluid and gas transport, pressure piping The practical trap: a 2 inch pipe is actually 2.375 inch outside diameter. A tube ordered as 2.000 inch OD will not fit a 2 inch pipe flange. Send the standard with the request, ASTM B221 for tube or ASTM B241 for pipe, and the ambiguity disappears before the order is placed. Seamless, Welded and DOM: Three Routes for Aluminum Tube Seamless extruded tube. A heated billet is pressed through a die around a fixed or floating mandrel, so the metal welds to itself as it exits and leaves no longitudinal seam. Grain structure is uniform around the circumference, concentricity is excellent and pressure capability is the highest of the three. This is the route for hydraulic lines, high-pressure pneumatic tube, heat exchanger elements and critical structural members. Welded (ERW) tube. Strip is roll-formed into a cylinder and welded along the longitudinal seam, with the bead normally scarfed inside and out. It is the economical route, particularly above roughly 100 mm outside diameter. The weld seam is metallurgically distinct from the parent metal, so ERW is best kept to handrails, furniture, structural tube and low-pressure fluid lines. Drawn-over-mandrel (DOM) tube. Welded tube is cold-drawn over a mandrel, which work-hardens the wall, refines the grain and tightens dimensions substantially. The result is precision bore and outside diameter, a smoother surface and higher mechanical properties than the as-welded product. DOM is the specification for hydraulic and pneumatic cylinder tubing and precision shafts. One rule governs the choice where forming is involved: if the tube will be bent, flared or swaged, specify seamless or DOM. The weld seam of ERW tube tends to crack or thin on the outside of a tight bend. If ERW is unavoidable, keep the seam on the neutral axis of the bend to reduce crack risk. Alloy Selection by Duty 6061-T6 is the structural workhorse with a minimum yield of 240 MPa and tensile of 260 MPa; it welds and machines well and is the default for framing, handrails, machinery frames and transport equipment. Welding drops the heat-affected zone to roughly 60 to 70 percent of T6 strength, so welded assemblies need a design allowance. 6063-T5, at 110 MPa yield and 160 MPa tensile, extrudes cleanly and takes the brightest anodized finish, which suits visible architectural tube, irrigation, condensate lines and decorative trim. 7075-T6 is the strongest alloy in common commercial use, with yield around 503 MPa and tensile around 572 MPa, and it is reserved for weight-critical work such as motorsport and aerospace components. Its corrosion resistance is poor and it is not welded conventionally, so it is the wrong answer near salt water or in a welded assembly. 5052 and 5083 are non-heat-treatable marine alloys with excellent salt-water and chemical resistance, and 5083-H116 reaches about 215 MPa yield. 3003-O is the classic drawn tubing for refrigeration, air conditioning and low-pressure fluid transport: low strength, excellent formability, brazed into headers and bent into coils. Pressure, Fatigue and Bend Limits For thin-wall tube under internal pressure, use the hoop stress relationship P = (2 x S x t) / D, where S is allowable stress, t is nominal wall thickness and D is outside diameter. Take a 6061-T6 tube at 50 mm outside diameter with a 3 mm wall, a yield of 240 MPa and a safety factor of 4: the allowable working pressure works out at approximately 7.2 MPa, with burst at yield around 28.8 MPa. Use a safety factor of 3 to 4 for cyclic or uncertain service and a factor of 2 only for static, well-understood duty. Pressure piping also needs delivery against ASTM B241 rather than B221 alone. Bending is the second check. A common rule for cold rotary draw bending is a minimum radius of about two times the outside diameter, and radii down to half the outside diameter require mandrel bending to stop the inside wall wrinkling or collapsing. Temper dominates formability: annealed O temper bends to roughly one times diameter and can be aged afterwards, T4 bends to about two times diameter, and T6 cracks at tight radii so it should not be taken below roughly three times diameter without a mandrel and likely pre-heating. Where cyclic loading is the design driver, 6061-T9, which is T6 cold-worked after aging, raises fatigue strength significantly at the cost of ductility; bend first and age to T9 afterwards. Tolerances, Concentricity and Documents Per ASTM B221 and EN 754-7, outside diameter is held to plus or minus 0.10 to 0.25 mm depending on size, wall thickness to plus or minus 10 percent of nominal, roundness to 1 percent of outside diameter or better, and straightness to 0.8 mm per 1,000 mm. Standard cuts hold plus or minus 1 to 5 mm and precision cuts plus or minus 0.1 to 0.5 mm. Concentricity is where tube differs most from angle or flat bar: seamless extruded tube holds around 5 percent wall variation around the circumference and DOM tube around 2 percent. For a press fit into a header or a precision boss, specify the concentricity you need rather than assuming the default is tight enough. Every order ships with a mill test certificate to EN 10204 3.1 carrying measured mechanical properties, chemical composition and dimensional records, issued against ASTM B210, B221, B241 or EN 754 as the project requires. Finishes include mill finish, anodizing at AA10, AA15 or AA20 for visible handrails, powder coating at 60 micrometers and above, and PVDF for high-UV or coastal sites. Minimum order quantity is 500 kg, and standard bars are supplied in 6 m lengths in brown paper wrapping.
Q: Is an aluminum tube the same thing as an aluminum pipe?
A: No, and mixing them up costs fittings that will not seat. Aluminum tube is specified by exact outside diameter and wall thickness under ASTM B210, B221 or B345, and is used for structural work, heat exchangers, furniture and precision frames. Aluminum pipe is specified by nominal pipe size and schedule under ASTM B241 or B429, and carries fluid and gas. The trap is that NPS 2 inch pipe is 2.375 inch outside diameter, so a 2 inch tube will not fit a 2 inch pipe flange.
Q: Seamless, welded or DOM tube — which should I specify?
A: It depends on what the tube has to do. Seamless gives the highest pressure rating and the cleanest bore, so it suits hydraulic lines, high-pressure pneumatic work and critical structural tube. Welded ERW is the most economical route, especially above roughly 100 mm outside diameter. DOM gives the tightest dimensional tolerance and the best mechanical properties, which is what hydraulic and pneumatic cylinder tubing needs. If the tube will be bent, flared or swaged, specify seamless or DOM.
Q: Can 6061-T6 aluminum round tube be bent without cracking?
A: It depends on bend radius, wall thickness and temper. The general rule for cold rotary draw bending is a minimum radius of about two times the outside diameter; tighter radii down to half the diameter need mandrel bending to prevent the inside wall collapsing. T6 temper has limited formability and is risky below roughly three times diameter. For tight radii, form in annealed O temper and age to T6 afterwards, or step down to T4 for moderate bends.
Q: How do I calculate the burst pressure of 6061-T6 round tube?
A: Use the thin-wall hoop stress formula P = (2 x S x t) / D, where S is allowable stress, t is wall thickness and D is outside diameter. For a 50 mm outside diameter, 3 mm wall 6061-T6 tube with 240 MPa yield and a safety factor of 4, working pressure is about 7.2 MPa and burst at yield about 28.8 MPa. Use a safety factor of 3 to 4 for cyclic service and confirm delivery against ASTM B241 for pressure piping.
Q: Do you supply seamless extruded aluminum tube?
A: Yes, as a port-hole die extrusion with no seam. Seamless is the right choice where pressure or fatigue matters; welded and DOM cover most structural and decorative work at lower cost.
Q: Seamless, welded or DOM — which should I specify?
A: Seamless for pressure and fatigue duty, DOM where concentricity and a clean bore matter, welded ERW for general structure and appearance. Send the duty and we will say which route fits.
Q: What is the minimum order for aluminum tube?
A: 500 kg per section. Mixed sizes can be consolidated into one shipment.

=== Aluminum Square Tubes ===
URL: https://www.linkedalu.com/products/standard-aluminum/square-tubes/aluminum-square-tubes.html
Summary: Aluminum square and rectangular tube selection with a practical load-span guide, bending limits and machining data, supplied cut to length, drilled and labeled from 6063-T5, 6061-T6 or 6005-T5.
- Alloy & Temper: 6063-T5 standard; 6061-T6 and 6005-T5 available
- Profile Type: Extruded square and rectangular hollow tube
- Stock Sizes: 20 x 20 mm to 100 x 100 mm square; rectangular up to 150 x 50 mm
- Wall Thickness: 1.5 mm to 6.0 mm in stock tooling
- Standard Length: 6 m mill length, cut to your BOM or cut list
- Straightness: 0.5 mm per meter after tension stretching
- Cutting & Hole Tolerance: +/-0.1 mm cut length; +/-0.15 mm hole position from datum
- Threads: M3 to M12, 6H class, tapped or thread milled
- Surface Finish: Anodized AA10/AA15/AA20 with nickel salt sealing; powder coat; PVDF
- Standards & Certification: GB/T 5237.1, EN 755-9; EN 10204 3.1 mill test certificate
Two Ways to Buy Aluminum Square Tube The first is a standard size. If your design calls for 50 x 50, 40 x 40, 80 x 40 or something similar, the die almost certainly exists already, which means no tooling charge: tell us the alloy, wall thickness, finish and cut length and the tube is produced against a live section. The second is a custom section. A specific corner radius, an unusual wall thickness or a size that sits off the catalog means a new die cut and extruded to your drawing. Either way the tube arrives cut to length, drilled or tapped where the design needs it, and labeled to match your bill of materials. Standard stock tooling covers square sections from 20 x 20 mm to 100 x 100 mm and rectangular sections up to 150 x 50 mm, with wall thicknesses from 1.5 mm to 6.0 mm. Custom die lead time is typically 10 to 14 days. Square Tube or Rectangular Tube? The choice comes down to the direction the load acts in. Square tube is equal in both directions, so it is the right answer for vertical posts, columns and railing uprights where the force could arrive from any side. Rectangular tube puts more material into the tall direction, which is where bending resistance comes from. For a horizontal beam carrying weight across a span, an 80 x 40 section in the vertical orientation beats 50 x 50 on stiffness for roughly the same weight per meter. As a working rule: if the part stands upright and takes compression, square is usually right; if it spans horizontally and takes bending, rectangular is usually more efficient. Load and Span: A Starting Point, Not a Certification Span Light load (under 30 kg) Medium load (30-100 kg) Heavy load (over 100 kg or point load) Up to 0.8 m 30 x 30 x 2.0 mm 40 x 40 x 2.5 mm 50 x 50 x 3.0 mm 0.8-1.5 m 40 x 40 x 2.5 mm 50 x 50 x 3.0 mm 60 x 40 x 3.0 mm 1.5-2.5 m 50 x 50 x 3.0 mm 60 x 40 x 3.5 mm 80 x 40 x 4.0 mm Over 2.5 m Send us the details 80 x 40 x 4.0 mm Needs proper calculation This table assumes 6063-T5 with evenly distributed load and simple supports. There is no single answer without knowing whether the load is concentrated or distributed, whether the member is supported at both ends or cantilevered, and whether the duty is static or dynamic. Stepping up to 6061-T6 often allows a smaller section for the same load, because its yield strength is roughly 50 percent higher than 6063-T5. If failure could hurt someone, on a walkway, a raised platform or a vehicle structure, do not use a table: send the load case and we will check the section properly. 6063-T5 or 6061-T6? Property 6063-T5 6061-T6 Tensile strength 160 MPa 290 MPa Yield strength 110 MPa 240 MPa Anodized appearance Clean, bright, even Grayish, less uniform Bending Good Poor without annealing Welding Acceptable, light loads Excellent The short answer: decorative or lightly loaded work uses 6063-T5; structural, welded or safety-related work uses 6061-T6. Welding derates 6061-T6 by roughly 40 to 50 percent in the heat-affected zone, effectively dropping it to a T4 condition, so structural welded assemblies must either account for that in the calculations or be restored by post-weld solution treatment and aging. We also supply 6005-T5 for solar mounting and rail applications, since it is stronger than 6063-T5 and still extrudes at sensible speeds. Bending Limits for Square Tube Small sections bend easily and large sections do not. Sections up to about 40 x 40 mm bend reliably with standard tooling, while 50 x 50 mm and above usually need a generous radius and a wall thick enough to support the bend. A practical minimum bend radius for square tube is roughly three times the section size, measured to the centerline; tighter than that and the inside wall starts to cave. 6063 bends better than 6061, and 6061-T6 tends to crack on tight bends unless it is annealed first, which adds cost and time. Why Two Quotes for the Same Tube Differ Identical dimensions on paper can be a different product in reality. A 50 x 50 x 3.0 mm tube may be produced at an actual wall of about 2.7 mm if the supplier runs to the loose end of the tolerance, which means less aluminum per meter. Billet quality shows up after anodizing, and straightening method shows up after cutting: tension-stretched tube stays straight where roll-straightened tube can spring back. Delivery condition is the last variable, since a raw bar costs less than a pre-cut, deburred piece until you add your own sawing and labor. What We Do in the Factory Billets are heated to 480-520 degrees Celsius and pushed through the die. 6063 runs fast; 6061 runs slower and wears tooling harder, which is part of why it costs more. Section dimensions are held to GB/T 5237.1 and checked every 50 bars. Every tube then passes through a tension stretcher at 1 to 3 percent past yield, which is what keeps a bar straight after it is cut into ten pieces. Cutting is done on precision saws to plus or minus 0.1 mm with square, burr-free ends, and cut lists can come straight from your BOM or drawing. CNC drilling is programmed from a single datum and holds hole position to plus or minus 0.15 mm, with tapping to 6H class from M3 to M12 and thread milling where the design calls for it. Rotary draw and roll bending handle curved sections after evaluation of radius, section and wall thickness. Finishing is in-house: anodizing to AA10, AA15 or AA20 with nickel salt sealing, and powder coating in standard polyester, super-durable polyester or PVDF. Because machining and coating happen in the same building, a tube never leaves the site between operations. Packing puts a protective PE film on visible faces, foam separators between layers and waterproof stretch wrap over the bundle, then pallets or steel-reinforced crates for export, with labels on every piece for kit orders. Every shipment includes an EN 10204 3.1 mill test certificate listing heat numbers, chemical composition and mechanical results including tensile strength, yield strength, elongation and Webster hardness. Third-party inspection by SGS, TUV or Bureau Veritas can be arranged before dispatch. Standard mill length is 6 m and minimum order quantity is 500 kg.
Q: Do you hold stock, or is everything custom extruded?
A: We maintain existing tooling for dozens of standard sizes, from 20 x 20 mm to 100 x 100 mm square and up to 150 x 50 mm rectangular, with wall thicknesses from 1.5 mm to 6.0 mm. Standard profiles carry no die charge. For a custom profile, custom wall arrangement or a specific corner radius we manufacture new tooling in-house, with a typical die lead time of 10 to 14 days.
Q: What tolerances can you hold on cut length and hole positions?
A: Standard extrusion cross-sections comply with GB/T 5237.1 and EN 755-9. For precision post-processing, CNC cutting holds lengths to plus or minus 0.1 mm and hole-to-hole location to plus or minus 0.15 mm from a single datum. If an assembly needs tighter linear or twist tolerances, key surfaces can be precision milled after extrusion to bring them inside the standard range.
Q: How do you prevent surface scratching during sea freight?
A: Every tube receives a protective PE film on visible faces. Profiles are bundled with interleave foam separators to stop metal-to-metal contact, wrapped in waterproof stretch film and packed into steel-reinforced wooden crates. For high-density shipments we can nest smaller profile sizes inside larger tubes to optimize container space, and labeled pieces keep kit orders in sequence on arrival.
Q: What is the effect of welding on 6061-T6 aluminum tube strength?
A: Welding heat reduces yield strength in the heat-affected zone of 6061-T6 by roughly 40 to 50 percent, effectively dropping it to a T4 temper condition. For structural or load-bearing welded assemblies you must either account for that derating in your structural calculations or restore the temper with post-weld solution heat treatment and artificial aging. Both routes are valid; the important thing is deciding which one applies before the drawing is released.
Q: What sizes can you supply?
A: Stock dies cover the common sizes up to 200 mm. Anything outside that, or a wall thickness the stock die cannot hold, runs on a new die to your section.
Q: What wall thickness?
A: From 0.8 mm, with the practical limit set by the section and the alloy.
Q: What is the minimum order?
A: 500 kg per section, whether or not a new die is required.

=== Aluminum I-Beam and T-Profile Extrusions ===
URL: https://www.linkedalu.com/products/standard-aluminum/t-shape-aluminum-profiles/aluminum-i-beam-t-profile.html
Summary: Custom extruded aluminum I-beam and T-profile sections for truck bodies, trailers, machine frames, partition walls, ceiling grids and architectural reveals, with mill finish or anodized supply and full dimensional records.
- Alloy & Temper: 6063-T6 standard; 6061-T6 for structural duty, 6063-T5 for visible profiles
- Profile Types: Extruded I-beam and T-profile: equal T, unequal T, sharp or radiused corners
- I-Beam Envelope: Depth up to approx. 300 mm; flange width up to approx. 200 mm
- Web & Flange Thickness: 2 mm to 25 mm depending on depth
- Reference Sizes: 50 x 30 mm to 300 x 150 mm (h x b)
- Weight per Meter: 0.95 kg/m at 50 x 30 mm up to 18.5 kg/m at 300 x 150 mm, theoretical
- Hardness: 12 HW min.
- Standard Length: 5.8 m; 6.0 m by project review
- Dimensional Tolerance: Depth +/-0.5 to +/-1.5 mm; flange width +/-0.5 to +/-1.0 mm; wall +/-10 %
- Straightness & Twist: 0.8 mm per 1,000 mm; twist 0.5 degrees per 1,000 mm
An Aluminum I-Beam Is Extruded, Not Rolled Lightweight structural aluminum profiles — I-beam, T and tapered-wall sections — are extruded in 6063-T5/T6 or 6061-T6 and used where a steel section is heavier than the job needs. Wall from 0.8 mm, circumscribed circle to 540 mm, and 500 kg per profile whether or not a new die is cut. A steel wide-flange beam is hot-rolled and can run 600 mm deep. An aluminum I-beam is pushed through a die in a hydraulic press, so the section is limited by what the press can take and what the die can hold. That is why commercial aluminum I-beams rarely exceed 250 to 300 mm depth, and why the flange is normally uniform in thickness with no taper. These are not defects; they are the geometry that comes with extrusion, and designing around them is what makes aluminum work in a structural frame. Linkedalu Metal Group Co., Ltd extrudes custom aluminum I-beam and T-profile sections for structural framing, stiffening, machine bases, transport equipment and architectural work where steel is simply heavier than the specification allows. Mill test certificates against GB/T 5237, EN 755-9 or ASTM B221 ship with every order. Aluminum vs Steel: An Honest Comparison Property Steel (ASTM A992) Aluminum 6061-T6 (ASTM B221) Density 7.85 g/cm3 2.70 g/cm3 Tensile strength 400-550 MPa 260 MPa min. Yield strength 250-345 MPa 240 MPa min. Elastic modulus 200 GPa 69 GPa Thermal expansion 11.6 x 10-6 /C 23.1 x 10-6 /C Manufacturing Hot rolled Extruded At an equal cross-section a 6061-T6 aluminum beam carries roughly 35 to 40 percent of the load a steel beam carries, at about one-third the weight. Two numbers are routinely missed. Aluminum's elastic modulus is about one-third of steel's, so a same-size aluminum beam deflects roughly three times more under the same load. Its thermal expansion is about twice steel's, so long-span members need movement allowed at the connection rather than only at the surface. Stiffness: What 69 GPa Costs You, and How to Recover It Because deflection is rarely fixed by changing alloy, it is fixed by changing geometry or span. Three levers work: go deeper, since moving from a 100 mm to a 150 mm aluminum I-beam roughly doubles the moment of inertia; add internal stiffening ribs in the extrusion, which puts material where stress is highest for little weight penalty; or accept the lower stiffness and reduce the unsupported span with closer supports. A drawing review will tell you which lever the section geometry allows. Extrusion also lets the cross-section be designed for the load path rather than for a rolling mill, using tapered wall thickness, a hollow tubular web or internal ribs. Those are the design moves that let aluminum win on specific strength. Welding follows the usual aluminum rules: 6061-T6 welds cleanly with TIG or MIG using 4043 or 5356 filler, and the heat-affected zone loses temper, dropping to roughly T4 strength in the weld zone. Aluminum I-Beam Sizes, Tapered Walls and Tolerances On presses from 500 MT to 5,000 MT the practical envelope is a depth up to about 300 mm, a flange width up to about 200 mm, web and flange thickness from 2 mm to 25 mm depending on depth, and a weight per meter that normally stays below 15 kg/m. Beyond about 300 mm depth the web cools slowly while the flanges cool fast, and the differential contraction warps the section. Section h x b (mm) Web t (mm) Flange t (mm) Weight (kg/m) 50 x 30 3.0 4.0 0.95 80 x 40 4.0 5.0 2.10 100 x 50 4.5 6.0 3.20 150 x 75 5.5 8.0 6.50 200 x 100 6.5 10.0 11.00 300 x 150 8.0 12.0 18.50 Weights are theoretical and for reference only; the certified figure travels on the mill test certificate. Dimensional tolerances run to depth plus or minus 0.5 to 1.5 mm depending on size, flange width plus or minus 0.5 to 1.0 mm, web and flange thickness plus or minus 10 percent of nominal, straightness within 0.8 mm per 1,000 mm, twist within 0.5 degrees per 1,000 mm and web flatness within 0.5 percent of web height. Tighter tolerances slow the press, add inspection and sometimes force die modification, so they are worth specifying only where the assembly needs them, such as machined mating faces and bolted flange connections. T-Profile Variants and Alloy Choice Four decisions change what a T-profile does. An equal T, where flange width and stem height are similar, is the default for stiffeners, ceiling grids and partition frames because loading across the flange is symmetric. An unequal T, with a flange wider than the stem, suits display frames, architectural reveals and signage holders where the mounting surface needs more contact than the stem needs for stiffness. Sharp corners give a clean architectural line with a modest stress concentration, while radiused corners distribute stress better, extrude more easily and are safer to handle, which is why visible architectural T profiles almost always use radiused corners. 6061-T6, with a minimum tensile of 260 MPa and yield of 240 MPa, is specified for structural T-bars, stiffeners, welded machine frames and transport equipment. 6063-T5, at 160 MPa tensile and 110 MPa yield, is the default for visible architectural T profiles, ceiling grids and reveals because it anodizes bright and uniformly. 6060-T5 serves European specifications with tighter visual standards, and 5052 or 5086 covers marine plate and secondary members. A structural T-profile is not a T-slot profile. T-slot extrusions such as 2020, 2040, 4040 and 4080 are a separate product family with slots machined into the flange to accept T-nuts for modular framing. They look similar and do different jobs, so say explicitly that you want a structural T. Where These Sections Work Transport equipment is aluminum's home ground: an aluminum 6061-T6 I-beam frame can cut frame weight by 40 to 50 percent against a steel equivalent and convert that saving directly into payload. Machine builders move to aluminum I-beams when the machine has to be repositioned regularly or when corrosion matters, as in food processing and wash-down areas. T-profiles in 6063-T5 sit behind suspended ceiling grids, partition framing and architectural reveals, and a T-profile bonded to the back of a flat panel raises the panel's moment of inertia so a flexible sheet becomes structural. Marine structures such as boat lifts, dock frames and gangways use aluminum because it needs no painting at the waterline. Fabrication covers cut-to-length, drilling, mitering, welded sub-assemblies and labeling to your call-up list. Standard length is 5.8 m, with 6.0 m available by project review, and finishes run from mill finish through anodizing at AA10, AA15 or AA20, architectural powder coating at 60 micrometers and above, and PVDF for high-UV or coastal exposures. Minimum order is 500 kg for a new die and 200 to 500 kg for sections already in the die library.
Q: Can an aluminum I-beam replace a steel I-beam in my frame?
A: Sometimes, depending on what the frame does. A 6061-T6 aluminum I-beam at the same cross-section carries roughly 35 to 40 percent of the load a steel beam carries, but weighs about one-third as much. Aluminum wins for weight-sensitive structures such as trailers, truck bodies, railcar components, portable equipment and marine frames, and for corrosion-exposed sites. Steel still wins for stationary high-load applications and very large spans where extrusion cannot reach the depth.
Q: An aluminum beam of the same size deflects more than steel. What do I do?
A: There are three practical options. Go deeper, since a 150 mm aluminum I-beam roughly doubles the moment of inertia of a 100 mm section. Add internal stiffening ribs to the extrusion so material sits where stress is highest. Or accept the lower stiffness and reduce the unsupported span with closer support spacing. Aluminum's modulus of 69 GPa against steel's 200 GPa means deflection is almost never solved by switching alloy, only by changing section geometry or span.
Q: Should I choose an equal T or an unequal T profile?
A: Equal T, where flange width is close to stem height, suits symmetric duty: ceiling grids, partition frames and panel stiffeners where load is distributed across the flange. Unequal T, with a flange wider than the stem, suits cases where the mounting surface needs more contact area than the stem needs for stiffness, such as display frames, architectural reveals and signage holders. If you are unsure, equal T is the safer default and easier to source from existing dies.
Q: Is a T-profile the same as a T-slot profile?
A: No, and the two are quoted very differently. A T-profile is a structural T-section with a flange and stem, used as a stiffener, ceiling grid, reveal or partition frame. A T-slot profile in the 2020, 2040, 4040 or 4080 industrial framing family has slots machined into the flange to accept T-nuts and bolts for modular assembly. They look vaguely similar but serve entirely different functions, so state clearly which one your project needs.
Q: Can you extrude an I-beam with sharp corners?
A: Yes. Sharp square corners are a die question, not a rolling limitation, and we cut the die to your section. Tapered flanges are also available where the design needs them for stiffness or fit.
Q: What is the largest I-beam section you can extrude?
A: Set by the 540 mm circumscribed circle of our largest press, not by the profile name. Send the section drawing and we confirm the die and press before quoting.
Q: Why aluminium rather than steel for a beam?
A: Weight. Aluminium is about a third the density of steel at roughly 69 GPa against 200 GPa, so the section is usually deeper to recover stiffness, and the frame ends up lighter for the same load.

=== Aluminum U-Channel Profiles ===
URL: https://www.linkedalu.com/products/standard-aluminum/u-shape-aluminum-profiles/aluminum-u-channel-profiles.html
Summary: Extruded aluminum U-channel engineered for glass retention, panel systems, sliding tracks and edge protection, with slot tolerances, wall-thickness ratios and alloy specified to your project rather than to a catalog.
- Alloy & Temper: 6063-T5 standard; 6061-T6, 6060-T5, 5052/5005 by duty
- Profile Type: Extruded U-channel with equal or unequal legs (not C-channel)
- Adjacent Wall Ratio: 2:1 or less to avoid quench warping
- Cross-Sectional Tolerance: +/-0.2 to +/-0.5 mm up to 100 mm; +/-0.5 to +/-1.0 mm above 100 mm
- Wall Thickness Tolerance: +/-10 % of nominal
- Standard Length: 6.0 m mill length
- Cut Length Tolerance: +/-0.1 to +/-0.5 mm precision cut; +/-1 to +/-5 mm standard cut
- Straightness & Twist: 0.8 mm per 1,000 mm; twist 0.5 degrees per 1,000 mm
- Surface Finish: Mill finish, anodized AA10/AA15/AA20, powder coat 40 um+, PVDF 2/3/4-coat
- Standards: GB/T 5237.1, EN 12020-2, ASTM B221; MTC to EN 10204 3.1
A U-Channel Is a Slot, a Track or a Frame U-channel with equal or unequal legs in 6063-T5, section tolerance ±0.2 to ±0.5 mm up to 100 mm, straightness 0.8 mm per metre, supplied in 6.0 m mill lengths or cut to ±0.1 mm. 500 kg per profile. Two legs, a base and a 90 degree inside corner looks like the simplest profile to specify. It usually is not, because the open slot that makes a U-channel useful is also what makes it hard to extrude: two thin legs standing on a flat base are a metal-flow problem at the press and a warping problem after the quench. What the pocket does defines the specification. A slot that holds something — frameless glass retention in storefronts and balustrades, panel receivers in facade cladding, signage frame inserts. The legs are the bearing surface, so leg height and parallelism decide how cleanly the mating part slides in. A track that something slides along — sliding door rails, drawer slides, machine linear guides, cable carriers. The base must be flat, the inside corner consistent and the surface must not gall against the moving part. A frame that caps an edge — countertop and panel edge protection, worktop trim, decorative reveals, where finish, corner radius and straightness are what get judged. Linkedalu Metal Group Co., Ltd extrudes custom aluminum U-channel for glass retention, panel systems, sliding tracks, edge protection, cable management and structural framing, with mill test certificates against GB/T 5237, EN 755-9 or ASTM B221 on every order. U-Channel vs C-Channel A U-channel has two straight legs at 90 degrees to the base. A C-channel adds an inward return lip on each leg, which stiffens the section against local buckling and gives a screw head something to bite into. Use U-channel where the mating piece needs a clean sliding fit and the load is modest, such as glass, panels and light rails. Use C-channel where the section has to carry more load, mount to a substrate with self-tapping screws, or hold a rigid insert against pull-out. They look alike and behave differently. Wall-Thickness Ratio: The Silent Cause of Warping Hot aluminum leaving the die cools unevenly. Thick sections cool slower than thin ones, and the differential contraction distorts the profile as it leaves the press. The rule most extrusion designers work to is a ratio of 2:1 or less between adjacent wall thicknesses. A 3 mm leg next to a 1.5 mm tongue is fine; a 3 mm leg next to a 1 mm tongue will twist even when the rest of the section is in tolerance. On a U-channel the failures show up first at the inside corner radius and where the leg meets the base. We catch this at die design, and if a drawing arrives with a 4:1 ratio built in, we flag it before any steel is cut. Fixes include redistributing material toward the thin section, adding a fillet to ease the transition, or adding internal stiffening. CCD and Weight per Meter Two numbers decide whether a custom U-channel is economical to produce. The circumscribing circle diameter, the smallest circle enclosing the whole cross-section, extrudes efficiently between roughly 25 and 200 mm; below that the die work is fine and fragile, above it a larger press and slower speed are needed. Weight per meter is best kept around 1.5 kg/m or less, because heavier channels need slower press speeds, larger billet logs and more quench control. Neither constraint reaches a unit price until the first production run. Alloy Selection: Visible Work vs Structural Duty 6063-T5 is the default for architectural and visible work. It extrudes cleanly, anodizes uniformly and carries enough strength for glass retention, panel receivers, edge trim and light framing. 6061-T6 is the structural channel, with roughly double the yield strength at 240 MPa against 110 MPa, and is specified when the channel carries load, is welded into a frame, or sits in a high-vibration assembly. 6060-T5 serves European specifications for fine, clean sections with tighter visual standards, and 5052 or 5005 covers marine and chemical environments where corrosion dominates over strength. Tolerance Reality: What Extrusion Actually Holds No extruded profile is perfectly dimensioned, and the honest specification is the one the process can hold. Per GB/T 5237.1 and EN 12020-2, cross-sectional dimensions up to 100 mm hold plus or minus 0.2 to 0.5 mm, and dimensions above 100 mm hold plus or minus 0.5 to 1.0 mm. Wall thickness holds within 10 percent of nominal. Length holds plus or minus 1 to 5 mm on a standard cut and plus or minus 0.1 to 0.5 mm on a precision cut. Straightness is 0.8 mm per 1,000 mm or better, twist 0.5 degrees per 1,000 mm or better, and angularity between legs and base 1 to 2 degrees. Tighter tolerances slow the extrusion speed, add inspection steps, sometimes force a die modification and raise the price, so the useful question is whether the assembly actually needs them. A glass retainer that the glazier will shim on site can hold standard tolerance on slot depth; a sliding track that a roller rides against needs parallel legs and a flat base. State the application on the drawing and we will say which tolerances the specification needs. Where U-Channel Is Specified Glass retention is the largest single use. Anodized U-channel is the standard receiver for frameless glass in storefronts, office partitions and balustrade base shoes. The channel width must match the glass thickness, commonly 8, 10 or 12 mm, and the inside corner has to be smooth so the glass does not chip during installation. 6063-T5 with a clear or black anodized finish is the default. U-channel is also the insert receiver for ACM, HPL and decorative panel cladding, and the structural backbone of framed photovoltaic modules and many solar mounting rails, where a Class AA15 anodized finish has to survive 25 years of ultraviolet and salt-spray exposure. Machine guards and cable trays use 6063-T5 as standard and 6061-T6 where the guard must pass an impact test, and retail fit-out uses short runs under 500 kg from existing dies. Finishing, Fabrication and Order Flow Finish options are mill finish as standard supply, anodizing at Class AA10, AA15 or AA20 in clear, champagne, bronze or black, architectural-grade powder coating at 40 micrometers and above, and PVDF fluorocarbon coating in two, three or four coats for high-UV and coastal conditions. Fabrication covers cut-to-length, drilling, slotting, mitering and labeling to your elevation or call-up list, with slot tolerances held to plus or minus 0.15 mm where the mating part requires it and pieces packed in sequence so the installer works straight from the crate. Standard length is 6.0 m; minimum order is 500 kg for a new die and 200 to 500 kg for sections already in the die library.
Q: What tolerances can I expect on a custom aluminum U-channel?
A: Per GB/T 5237.1 and EN 12020-2, standard extrusion tolerances are plus or minus 0.2 to 0.5 mm on cross-sectional dimensions up to 100 mm, plus or minus 0.5 to 1.0 mm above 100 mm, and plus or minus 10 percent of nominal on wall thickness. Length holds plus or minus 1 to 5 mm on a standard cut and plus or minus 0.1 to 0.5 mm on a precision cut, with straightness within 0.8 mm per 1,000 mm. Tighter values are possible but slow the press and force extra inspection.
Q: My U-channel has a 4:1 wall-thickness ratio. Will it warp?
A: Likely, yes. The working rule is adjacent wall thicknesses of 2:1 or less. Beyond that, thick sections cool more slowly than thin ones during the quench and the differential contraction twists the profile as it leaves the press. On a U-channel this appears first at the inside corner radius and where the leg meets the base. We flag it at die design and propose one of three fixes: redistribute material toward the thin section, add a fillet to ease the transition, or add internal stiffening.
Q: Should I specify 6063-T5 or 6061-T6 for a U-channel?
A: 6063-T5 is the default for visible and architectural work. It extrudes cleanly, anodizes uniformly and holds sufficient strength for glass retention, panel receivers and light framing. Specify 6061-T6 when the channel has to carry load, when it is welded into a frame, or when it sits in a high-vibration assembly, because its yield strength is roughly double at 240 MPa against 110 MPa. For marine or chemical environments where corrosion dominates, consider 5052 or 5005 instead.
Q: What is the difference between a U-channel and a C-channel?
A: A U-channel has two straight legs at 90 degrees to the base. A C-channel adds an inward return lip on each leg, which stiffens the section against local buckling and gives a screw head something to bite into. Use U-channel where the mating part needs a clean sliding fit and the load is modest, such as glass retention, panel receivers and light sliding tracks. Use C-channel where the section carries more load, mounts with self-tapping screws, or holds a rigid insert.
Q: Standard sections or custom?
A: Both. Stock U and T sections cover most framing work; where the channel has to receive a specific panel or gasket, we cut a die to your section.
Q: What wall thickness?
A: From 0.8 mm. The upper limit depends on the section and the alloy, so send the drawing rather than asking for a maximum.
Q: What is the minimum order?
A: 500 kg per section, whether or not a new die is required.

=== CNC Machining of Aluminum Profiles ===
URL: https://www.linkedalu.com/products/cnc-machining-parts/high-precision-aluminum-parts/cnc-machining-aluminum-profiles.html
Summary: In-house CNC deep processing that turns extruded aluminum profiles into finished, bolt-ready components, with published tolerances, single-fixture multi-axis machining and synchronized anodizing or powder coating.
- Alloy & Temper: 6063-T6 extruded profiles; 6061-T6 machined components
- Machining Processes: Precision sawing, CNC drilling, tapping, milling, punching, profile bending
- Sawing Tolerance: +/-0.1 mm on straight and miter cuts
- Drilling Tolerance: +/-0.05 mm hole position, multi-surface in one fixture setup
- Milling Flatness: 0.05 mm on machined faces
- Threads: M3 to M16 internal threads; thread milling available
- Surface Roughness: Ra 0.8 to Ra 1.6 um on sealing and mating faces
- Maximum Profile Length: 6 m standard lines; 12 m on long-bed equipment
- Surface Finish: Anodizing, hard-coat anodizing or powder coating, sequenced with machining
- Quality & Certification: First-article inspection, in-process audits, 100 % final check, CMM metrology; ISO 9001:2015
Extrusion and Machining Under One Roof CNC machining of extruded aluminium profiles: drilling, tapping, milling, deburring and assembly on extrusion we produce ourselves, so the machined tolerance is measured against the die we cut rather than against an unknown supplier's section. Profiles from 0.8 mm wall and up to a 540 mm circumscribed circle, machined to ±0.05 mm on the features your drawing calls out. A raw aluminum profile is not a component until it has been cut, drilled, tapped and finished to the drawing. Linkedalu Metal Group Co., Ltd runs an independent CNC deep processing workshop alongside its extrusion presses, so the same facility that produces the section also machines it into a part that can be bolted straight into your machine, automation frame or structure. That removes the handling damage, freight cost and schedule risk that come with shipping raw profiles to a third-party machine shop. Because the profile geometry and the machining process are planned together, the cross-section can be optimized for the tooling that will follow. The classic problem of a profile that machines badly at a separate shop does not arise when the die designer and the process engineer sit in the same building. Machining Capabilities and Published Tolerances Process Capability Tolerance Precision sawing Burr-free miter and straight cuts with high surface finish +/-0.1 mm CNC drilling Multi-surface drilling in a single fixture setup for alignment +/-0.05 mm Thread tapping Metric and standard internal threads for hardware fastening M3 to M16 CNC milling Face and side milling, slotting, stepped pockets 0.05 mm flatness Stamping and punching High-volume hydraulic punching for uniform hole arrays Per specification Profile bending Stretch bending and roll bending for curved geometry Per specification Standard machining lines handle profiles up to 6 m long. For heavy industrial parts, long-bed equipment extends that to 12 m, subject to evaluation of the section blueprint. Surface roughness on sealing and mating faces is typically held between Ra 0.8 and Ra 1.6 micrometers where the drawing calls for it. Inside the Deep Processing Workshop The machining floor covers 3,000 square meters and houses more than 20 advanced CNC vertical and horizontal processing centers. High-speed multi-spindle drilling and tapping lines run at a capacity above 300 holes per hour, which is what makes high-density hole patterns on long profiles economic rather than a bottleneck. Metrology includes coordinate measuring machines, optical video measuring systems, digital height gauges and calibrated thread plug gauges. Quality control follows a fixed protocol: first-article inspection before a batch is released, in-process roving audits through the run, and a 100 percent final compliance check backed by full batch inspection reports. When a blueprint specifies a position or flatness limit, the production route is mapped to respect that limit rather than adjusted after the parts are made. Why Single-Fixture Machining Matters Geometric dimensioning and tolerancing is where most assembly problems originate. If a linear guide mounting plane is milled in one setup and its neighboring positioning pins are drilled in a second, the relationship between them depends on how accurately the part was re-clamped. Machining critical mating faces in a single fixture preserves parallelism and perpendicularity, so the finished assembly fits without on-site alignment. Where aluminum threads will be assembled and disassembled repeatedly, thread milling and stainless steel inserts give a more durable joint than a conventional tapped hole. Design for Manufacturability Support Send STEP, IGES, DWG or PDF files and our engineering team returns a complimentary design-for-manufacturability review that aims to reduce unit cost without changing function. Typical recommendations cover wall thickness that will vibrate during machining, threads placed too close to an edge, tolerances that the assembly does not actually use, and features that can be produced more cheaply in a different orientation. If no digital drawing exists, a physical sample can be sent and the metrology team will reverse-engineer it into an approved production drawing before quoting. Finishing, Sectors and Component Types Anodizing, powder coating and hard-coat anodizing are scheduled in step with machining, so a part can be anodized before milling to produce a contrasting metal look on the machined faces, or after machining for full edge protection. Sequencing is managed internally, which keeps lead times predictable. Typical components include robotic gantry beams, linear module actuators, automated sensor brackets and chassis frames for factory automation; SMT pick-and-place conveyor rails, assembly fixtures and test jigs for electronics manufacturing; lithium battery winding machine frames, stacking guide rails and power distribution racks for new energy equipment; and automated guided vehicle frames, conveyor guide tracks, warehouse rack couplers and medical bed frameworks for logistics and medical customers. Workflow and Lead Times Technical consultation, typically one working day. DFM review and optimization, one to two working days. Rapid CNC prototyping, three to seven working days. Mass production and quality control to the scheduled timeline. Specialized packaging and delivery, one to two working days. For standard parts with complete drawings, an itemized quotation is issued within 24 hours; complex multi-axis parts involving several sub-processes take one to two working days. Quotes break out material cost, machining fees and surface treatment separately so the cost drivers are visible. Prototyping orders are accepted from a single unit, and the minimum order quantity for production runs is 100 pieces. Cosmetic protection during machining uses custom soft-jaw fixtures, non-marring clamping pads and protective film, and finished parts travel individually wrapped in pearl cotton padding inside cartons to arrive undamaged.
Q: What is the maximum length of an aluminum profile you can machine?
A: Our standard automated CNC centers handle profiles up to 6 meters long without special setup. For large industrial components up to 12 meters we use long-bed specialty machines, and cutting, drilling, milling, tapping and bending can all be performed on those lengths. Send the cross-section drawing and the machining features for a technical evaluation, because the feasible length depends on the section stiffness as well as the machine bed.
Q: What tolerances can your workshop reliably hold?
A: For CNC drilling we hold a hole-to-hole center tolerance of plus or minus 0.05 mm, achieved by machining multiple faces in a single fixture setup. For milling we secure a flatness tolerance of 0.05 mm, and the precision automated saws hold length cuts within plus or minus 0.1 mm. Threads are produced from M3 to M16, and surface roughness on sealing faces is typically held between Ra 0.8 and Ra 1.6 micrometers.
Q: Can I place a low-volume order for prototyping?
A: Yes. We support new product development and accept prototyping orders from a single unit, with production quantities from 100 pieces. Low-volume engineering tests get the same inspection route as high-volume runs, including first-article inspection, so the sample you approve reflects how the part will actually be made. Drawings can be supplied as STEP, IGES, DWG or PDF, or a physical sample can be reverse-engineered.
Q: How fast can I expect an official quotation?
A: For standard parts with complete drawings we issue an itemized quotation within 24 hours. Complex multi-axis parts involving a number of sub-processes take one to two working days, because each operation has to be sequenced and costed. Every quotation breaks out material cost, machining fees and surface treatment separately, so you can see exactly which features are driving the unit price.
Q: What tolerances can you hold on a machined profile?
A: 0.05 mm on critical features, with the datum set from the extrusion rather than the raw bar so the machining follows the section that actually exists.
Q: Can you machine profiles we buy elsewhere?
A: We machine our own extrusion and bar stock. If the section is not ours, we usually quote the extrusion alongside the machining so the datum and the cut are controlled together.
Q: What is the minimum order?
A: 500 kg per section on the extrusion. Short machining runs on stock sections are quoted separately.

=== Machined Aluminum Parts for Robotics ===
URL: https://www.linkedalu.com/products/cnc-machining-parts/high-precision-aluminum-parts/machined-aluminum-parts-robotics.html
Summary: CNC machined aluminum components for robots, AGVs, linear actuators and AI vision systems — joint housings, base plates, camera frames and sensor brackets, machined in 6061-T6 with in-house anodizing.
- Alloy & Temper: 6061-T6 standard; 7075-T6, 6063-T5, MIC-6 cast plate
- Typical Components: Robot joint housings, actuator base plates, vision camera frames, AGV chassis plates, sensor brackets
- Bearing Bore: H7 tolerance (+0.015 / 0 mm on a 30 mm bore)
- Bore Coaxiality: 0.02 mm or better between two bearing seats
- Flatness: 0.05 mm over 1,500 mm on rail mounting surfaces
- Hole Position: +/-0.05 mm from datum
- Threads: 6H class, go / no-go gauged; thread milling and Helicoil inserts available
- Surface Roughness: Ra 0.8 to Ra 1.6 um on sealing faces
- Quantity Range: Minimum order 50 pieces; prototypes and production batches on the same equipment
- Surface Finish & Inspection: In-house anodizing or hard anodizing; CMM and granite-plate inspection data supplied
Aluminum Parts That Move 6063 aluminium parts for robot assembly and automation — brackets, mounts, linear-rail bases and frame members — machined from extrusion we run, drilled to your pattern and finished in-house. 500 kg per profile; circumscribed circle to 540 mm. Robot arms move, AGVs carry loads and vision systems inspect at micron-level accuracy. The aluminum parts inside those machines are not passive: they are under stress, in motion, and they set the ceiling on how precise the whole system can be. Linkedalu Metal Group Co., Ltd machines those components in the low and medium volumes robotics companies actually buy. These parts share a profile: they are not catalog items, they usually have thin walls and tight bores, several faces must be square to each other, and the order is often fifty pieces this month and a hundred next quarter. Send a STEP file and the part is machined, anodized and shipped from one supplier. Robot Arm Joint Housings and Connecting Arms Joint housings form the skeleton of a collaborative or industrial arm. They are typically cylindrical or box-shaped with a bearing bore at each end and mounting flanges on the sides. The recurring problem is that the wall may be 3 mm or less, and as soon as the part is clamped for boring it deforms slightly. The bore is finished, the clamp is released, and the hole springs back out of round, so the bearing does not seat properly and the joint has play from day one. The answer is fixturing. Pie-shaped soft jaws and expanding mandrels spread clamping force evenly around the circumference, holding the part without squeezing it oval. Bearing bores at both ends are finish-bored in one setup on a 4-axis machine, so coaxiality is governed by the machine's own alignment rather than by re-fixturing, and the flange faces are milled flat in the same setup so they stay perpendicular to the bore axis. Linear Actuator Base Plates and Stress Relief A linear module base plate is the long aluminum plate that everything bolts to: the rail on top, the bearing blocks and the motor mount at one end. A plate around 1.5 m long behaves well during machining and badly afterwards. Roughing cuts release residual stress left in the plate by the aluminum mill, and the remainder comes out slowly, so the plate can bow by as much as 0.1 mm over the following weeks, which is enough to make a precision stage bind. We rough-machine the plate leaving about 0.5 mm on critical faces, send it through a thermal stress-relief cycle, then finish-machine. The rail mounting surface and the bearing housing seats are milled in one setup, and flatness is checked on a granite surface plate with a dial indicator. For a plate 1.5 m long we hold 0.05 mm flatness. Rail bolt holes are thread-milled rather than tapped so they sit exactly on position and perpendicular to the mounting surface. Vision System Frames and Camera Mounts Machine vision is used for inspection, pick-and-place and autonomous navigation, and the camera and light are carried on aluminum frames that position them at precise angles and distances from the target. If the mount is off by 0.2 mm, the calibration is off. These frames commonly have several mounting faces at different angles for the camera, the light and the gantry. We machine them on 3, 4 and 5-axis CNC so multiple faces can be reached without breaking the setup. All critical mounting holes are machined from the same datum, so their relative positions are controlled by the machine's positioning accuracy rather than by how carefully the part was re-clamped. Edges are deburred so cable routing slots cannot cut wiring. Anodizing is done in-house; black anodized frames are common on vision systems because they reduce stray reflections. AGV and AMR Chassis Plates Autonomous mobile robots run on aluminum chassis built from a base plate, a top deck, side panels and a battery compartment frame. A typical base plate might be 1,200 mm by 800 mm with mounting patterns for drive wheels, casters, lift mechanisms and sensor brackets. A bowed plate makes the vehicle track crooked, and an inaccurate drive unit hole pattern wears the tires unevenly. Large plates are held on a vacuum table so no clamp distorts the edges, and all hole patterns are programmed from a single reference corner, so drive unit, caster and sensor bracket holes relate back to the same origin with no accumulated error. Most AGV parts are 6061-T6. Sensor Brackets and Precision Fixtures Small precise parts position sensors, cameras and alignment tools on an automated line. A laser distance sensor needs its bracket to hold it at exactly the right height and angle, and a proximity switch needs its mounting hole dead center on the target path. Parts might be 50 mm by 30 mm by 20 mm with a dowel pin hole at 6H7, which leaves only microns of clearance. These are batch-machined on the CNC with multiple workholding stations. Once the program is proven on the first piece the rest come out identical, dowel holes are finish-reamed rather than simply drilled, and threads are milled for consistency. Tolerances We Hold Every Day Feature What we hold How it is checked Bearing bore diameter H7 (+0.015 / 0 mm on 30 mm bore) Bore gauge calibrated to ring standard Bore coaxiality 0.02 mm or better between two bearing seats CMM or test bar with dial indicator Flatness on rail mounting surface 0.05 mm over 1,500 mm Granite surface plate plus dial indicator Hole position +/-0.05 mm from datum CMM or height gauge Thread quality 6H class, no tear-out Go / no-go thread gauge Surface finish on sealing faces Ra 0.8 to Ra 1.6 um Surface roughness tester Materials stocked include 6061-T6 for general robotics, AGV parts and brackets; 7075-T6 for high-stress arm links and thin-wall structural parts; 6063-T5 for enclosure parts and cosmetic covers; and MIC-6 cast plate for flatness-critical vision bases. Volumes, Files and Finish CNC machining carries no tooling cost the way extrusion or die casting does, so small batches make sense. Prototype quantities and production runs in the hundreds are handled on the same equipment, with the minimum order quantity set at 50 pieces. Accepted file formats are STEP for solid geometry, IGES and Parasolid, and 2D PDF or DXF drawings for simpler parts; if only a drawing exists, the model can be created with an extra day allowed for CAD work. Anodizing and hard anodizing are done in-house, so parts do not leave the building between machining and finishing. Cosmetic surfaces are masked during clamping with soft jaws or protective film, and finished parts are packed individually rather than thrown into a bulk bin, which avoids the scratches that cause rejection at incoming inspection.
Q: Aluminum threads keep stripping in parts that are assembled repeatedly. What do you recommend?
A: Two approaches, often used together. First, we thread-mill instead of tapping, because a milled thread has a smoother surface finish and better dimensional control, so the bolt engages more evenly. Second, for holes that see frequent assembly we install stainless steel Helicoil inserts. The insert becomes the wear surface and the aluminum body simply holds it, so if a thread eventually wears you replace the insert rather than the whole machined part.
Q: We need a 1.8 meter base plate that stays flat. How do you guarantee that?
A: Residual stress is the enemy of long flat parts. We rough-machine the plate first, leaving about 0.5 mm on critical faces, then run a thermal stress-relief cycle before finish machining to final dimensions. The part is fixtured with vacuum or minimal clamping pressure to avoid introducing new stress, and flatness is inspected on a granite surface plate with the measurement data shipped alongside. For precision applications we also recommend letting the plate settle for 24 to 48 hours and re-checking before packing.
Q: We only need 50 pieces for a prototype build. Is that too small?
A: Fifty pieces is normal for us. CNC machining has no tooling cost the way extrusion or die casting does: we program from your STEP file, set up the workholding, machine the batch and ship. Unit price is naturally higher than a 5,000-piece order because setup time is spread over fewer parts, but small-batch work is not refused and the pricing is not inflated. Most robot and AI customers start with batches of 50 to 100 units.
Q: Can you match the anodized color of parts we already have from another supplier?
A: We can get close, but an exact match depends on the alloy composition and the original anodizing parameters. If you send a physical sample we will run a test piece and send it for your approval before processing the full batch, so nothing is anodized blind. For a new project we recommend ordering all visible parts from a single production run, which keeps the color consistent across the whole assembly.
Q: Which alloys do you machine for robot parts?
A: 6061-T6 for general structural parts, 7075 where strength per gram matters, and 6262-T6511 for parts that need high-speed machining with a good finish.
Q: Can you supply the part from bar as well as from extrusion?
A: Yes. Some robot parts start as bar, some as an extruded section that already carries the shape. We quote whichever route gives the lower finished cost.
Q: What is the minimum order?
A: Prototypes are quoted individually; series work is priced per drawing. There is no 500 kg floor on machined parts.

=== Europe Can't Make Its Own Aluminium Anymore — What 2026–2030 Looks Like for B2B Buyers ===
URL: https://www.linkedalu.com/insights/europe-aluminium-supply-squeeze-2026.html
Published: 2026-09-21
The opening scene A buyer in Stuttgart signs an extrusion contract in Q4 2026 expecting 12-month fixed pricing. Three months later, the mill calls to renegotiate because the 6063 billet cost has doubled. The buyer pushes back. The mill cancels the order. The buyer's production line flattens for six weeks. This is not a hypothetical. It is happening right now across Europe, and it has very little to do with "the Iran war" in the way most news coverage frames it. The deeper story is this: Europe lost the ability to make its own aluminium twenty years ago. It just did not notice, because global supply was cheap and the Gulf states were filling the gap. Now that the Gulf itself is damaged and the energy economics have flipped, the gap is visible to anyone running a procurement line. This article is the consolidated view of where Europe's aluminium supply stands in September 2026, why the extrusion billet premium has doubled since February, what CBAM actually requires of you in practice, and a 90-day playbook for buyers who cannot afford to be caught flat-footed. What 2026 actually looks like in European aluminium Metric 2025 figure 2026 figure Note European primary aluminium consumption 9.0 Mt ~9.5 Mt Whole continent, including UK, EFTA European primary aluminium production (whole continent) 3.4 Mt ~3.2 Mt Norway + Iceland + EU + others EU 27 primary aluminium production 1.2 Mt ~1.0–1.2 Mt Down from 2.9 Mt in 2005 EU 27 primary self-sufficiency ~13% <13% Structural, not cyclical Structural primary deficit (EU 27) ~5.6 Mt/yr ~6 Mt/yr Imports fill the gap EU 27 semis consumption (extrusion + sheet) ~7.0 Mt ~7.1 Mt Extrusions = 3.49 Mt of this EU 27 semis production capacity ~4.5 Mt ~4.4 Mt Curtailments ongoing Extrusion billet premium, 6063 ddp North Germany (Ruhr) $560–600/t (27 Feb 2026) $1,175–1,250/t (29 May 2026) Doubled in 90 days Sources: European Aluminium (industry data); Fastmarkets; Kpler Insight; ING commodity research; AL Circle trade statistics; Mining Weekly. Why Europe stopped making its own Producing one tonne of primary aluminium requires 13 to 16 megawatt-hours of electricity. Electricity is roughly 40% of total operating cost. When European wholesale power prices spiked after 2021, the arithmetic for smelting stopped working. Between 2021 and 2023, nearly half of EU primary smelting capacity was either temporarily curtailed or permanently shut. The 2005 → 2025 trajectory is striking: EU 27 primary output fell from 2.9 Mt to 1.2 Mt — a 60% decline in twenty years. Plant-level facts: Aldel (Netherlands) — offline since 2021. Restart uncertain. Uniprom KAP (Montenegro) — shut 2023. Speira Rheinwerk (Germany) — shut 2023. Alcoa San Ciprián (Spain) — curtailed 2021, restarted 2024, now near full capacity. Hedges locked through 2027, longer-term power options still under negotiation. Slovalco (Slovakia) — curtailed, restarted August 2026 with a €155 million state subsidy at 80 kt/year versus 165 kt nameplate. Century Aluminum (Iceland, Grundartangi) — output cut by two-thirds in 2026 after an electrical failure at the plant. Net change in EU primary capacity over five years: roughly 1.5 Mt less than in 2020. None of this is new. What is new is that the buffer of cheap Middle Eastern supply that disguised the gap for two decades is itself now damaged. The Iran war: 2.3 Mt of supply vanished in Q1 Before 28 February 2026, Europe imported about 20% of its primary aluminium from the Middle East. Today, three of the region's biggest smelters are operating under stress or force majeure: Plant Country Status (Sept 2026) Annualised loss vs pre-war EGA Al Taweelah UAE Force majeure declared 28 March 2026 after Iranian strikes. Only ~25% of reduction cells restarted. ~1.2 Mt Aluminium Bahrain (Alba) Bahrain Running at ~50% capacity as of April 2026. Recovery to ~80% by mid-2026. ~0.81 Mt Qatalum (Hydro 50% stake) Qatar Running at ~60% capacity due to energy constraints. ~0.32 Mt Combined ~2.3 Mt/yr Sources: Fastmarkets; Mining Weekly; Reuters; SANA citing US Geological Survey data. The Gulf states produced 6.16 Mt of primary aluminium in 2025 — roughly 8% of global output. The capacity currently offline in the UAE and Bahrain alone represents about 4.4% of global primary supply. Saudi Arabia's east-west pipeline was struck in March and remains off-line, with a 12+ month repair timeline. Saudi Aramco has notified European refiners of zero October crude allocations, extending September cuts. The Strait of Hormuz, through which roughly 20% of global oil and LNG flows, has been intermittently disrupted since the war began. The point is not that the war caused Europe's aluminium supply problem. The supply problem was already there. The war exposed it. The billet premium doubled — and what that means The benchmark European duty-paid aluminium premium (EPDc1) hit a 10-month high of $340 per tonne in December 2025 and has stayed in that band since. The extrusion-specific benchmark tells the sharper story: 27 February 2026: aluminium 6063 extrusion billet, ddp North Germany (Ruhr), $560–600 per tonne. 29 May 2026: same benchmark, $1,175–1,250 per tonne. That is a doubling in three months. For European extrusion mills, billet is typically 50% to 60% of the cost base. When the input doubles, the mill has three options: Pass the cost through to the buyer in a price increase. Cut its own margin until operating cash flow is uncomfortable. Curtail output — close shifts, idle presses, drop unprofitable product lines. In 2026, European mills are doing all three. Some will not survive the winter. For the buyer, the implication is direct: any new extrusion contract signed before 31 December 2026 should include an explicit billet-index clause with caps. A flat-price twelve-month contract for delivery in Q1 2027 is a money-loser for both sides of the table. Who supplies whom now (and what is rotating) Source Status 2026 Trend Buyer friction China ~26% of EU semis imports Growing volume, CBAM cost rising but tightening EPD docs High but improving Turkey Largest single supplier to Germany Q2 2026 (20,192 t), but volumes down 10.3% YoY Retreating on energy costs and currency pressure Low (compliance easy) GCC (UAE, Bahrain, Qatar) Severely damaged by Iran war Structural retreat through 2027 War-zone unreliability Russia Capped at 50 kt/year (26 Feb – 31 Dec 2026) Excluded Sanctioned India Growing capacity, mostly domestic Steady Low Vietnam Receives Chinese extrusion, re-exports to EU Growing, under origin-investigation scrutiny Origin-of-goods risk The German extrusion trade pulse for Q2 2026 captures the rotation: imports at 147,743 tonnes are down 4.2% YoY, exports at 77,863 tonnes are up 3.6% YoY. The net import dependency is still massive, but the supplier mix is shifting. Austria's exports to Germany are down 14% YoY. Italy, Romania, and Czech Republic are gaining share. The pattern is clear. Importers are still needed. China is filling the gap left by Turkey's retreat, the GCC's damage, and Russia's sanctions. The CBAM penalty on Chinese primary content is quietly forcing Chinese suppliers to tighten their own EPD documentation — a win for European buyers who previously could not get verifiable carbon data from Chinese mills. CBAM is no longer optional The Carbon Border Adjustment Mechanism entered its definitive financial-liability phase on 1 January 2026. For aluminium extrusions, this means: Quarterly CBAM declarations are mandatory for EU importers. Embedded emissions (smelter → billet → extrusion) must be documented. Default values (where actual data is missing) carry a significant cost penalty. EU importers bear the cost, but they pass it back to non-EU suppliers through price. On 15 September 2026, the European Parliament voted 464–50 to expand CBAM to 457 downstream product lines — more than double the European Commission's proposed 180. Parliament and Council must still negotiate the final text, but the direction is set: more extrusions will be in scope by 2027. Parliament is also considering lowering the aluminium CBAM reporting threshold from 50 tonnes to 5 tonnes per shipment — a change that would capture many smaller machined and fabricated aluminium components used in vehicles, doors, and solar panels. For the buyer, the practical checklist is short: Get the EPD (Environmental Product Declaration) from every extrusion supplier. Verify the primary smelter source for the aluminium billet. Demand ISO 14064 / 14067 LCA documentation. If your supplier cannot produce these documents by Q2 2027, qualify a second source now. The CBAM default value for aluminium is approximately €1,500 per tonne of embedded emissions as of 2026. If your supplier cannot verify actual emissions, that is the penalty you pay. That figure is bigger than the entire processing margin on most extrusion orders. A common misread (worth correcting before you plan) When procurement teams ask for "ISO 9001 certified" extrusion suppliers, they think they are filtering for quality. They are actually filtering for documentation discipline. The two are not the same. We have seen ISO 9001-certified mills ship 8% scrap against 0.4% from uncertified family mills. Certification tells you the supplier can write a procedure. It does not tell you whether the chemistry sheet on the back of a 6063-T5 extrusion is honest about hydrogen content (it usually is not), whether the die is worn (it usually is after 200 heats), or whether the surface treatment line has a chemistry bath in spec (it usually does not, by the third shift). The right filter for quality is a five-test audit on a sample order: chemistry verification, dimensional tolerance across the lot, surface treatment thickness and colour (ΔE), hardness at three points along the profile, and a metallurgical cross-section if the part is safety-critical. ISO 9001 comes after. The six questions engineers ask AI These are the questions buyers ask most often. Answers traceable to current public sources, not "industry experts." 1. Will European aluminium smelters reopen? Not at meaningful scale. The 2021–2023 closures were economic, not temporary. Restart requires wholesale electricity at €60/MWh or below. EU wholesale prices have not been there consistently since 2021 and will not return in the 2026–2030 horizon under current energy policy. The only European smelter with a credible restart story is Alcoa San Ciprián, which is already near full capacity on hedges through 2027. 2. Is the billet premium spike temporary? The current spike is geopolitical. The structural floor is structural. Even if the Iran war ended tomorrow, EU primary self-sufficiency is 13% and falling. The premium will not return to pre-2026 norms. Buyers should anchor their contracts to a 2026 base, not a 2019 base. 3. Where can Europe import primary aluminium from besides the Middle East? Norway (stable but limited capacity), Iceland (Century Grundartangi curtailed), Canada (working with US tariff complications under USMCA), Brazil (Hydro Paragominá, Votorantim CBA), Australia (limited). Russia is sanctioned. The supply map is unfriendly. The marginal supplier is China, but with CBAM cost stacking. 4. What is CBAM going to cost my extrusion order? Default value for aluminium: approximately €1,500 per tonne. Verified emission data reduces this to actual embedded carbon. For a verified Chinese mill with renewable energy certificates and smelter-of-origin documentation, the cost is €400–600 per tonne. The gap is the financial incentive to source carefully. Default-value exposure is a margin event. 5. Can Chinese extrusion mills meet European quality and tolerance standards? Yes, for standard ±0.2 mm tolerances on 6xxx alloys, and yes for anodizing quality up to ΔE 1. The capability exists. It is concentrated in roughly 10 to 15 large Chinese mills, not the long tail. For ±0.05 mm precision work, semiconductor-grade clean packaging, IATF 16949 PPAP at Cpk 1.33 or above, or full-volume hermetic assemblies, the answer is yes for a small set of qualified Chinese suppliers — and no for the rest. The capability question requires a per-supplier audit, not a country-level generalisation. 6. Should I sign a long-term fixed-price extrusion contract? Only with a billet-index clause and a force majeure carve-out for war-related Middle East disruption. Flat-price twelve-month contracts are uninsurable under current conditions. Anything signed in Q4 2026 will be re-priced by Q2 2027 if conditions persist. A two-year fixed price is a gamble you will lose. A 90-day playbook for B2B buyers If you are a B2B buyer of aluminium extrusions and you are reading this in September 2026: Days 1–30: Map your exposure Identify your top 5 extrusion suppliers and their primary smelter sources. Calculate your annual embedded carbon exposure: total tonnes × default factor. Identify any single-source extrusion contracts with no alternative supplier. Calculate what a billet premium doubling means for your 2027 cost base. Days 31–60: Press your suppliers Request written EPD and LCA documentation from each supplier. Request the smelter source for primary aluminium (smelter name, country, renewable share). Ask for CBAM quarterly reporting experience and any prior EU imports. Push for a billet-index clause on every Q1 2027+ order. Days 61–90: Qualify alternatives Identify 2 to 3 non-European extrusion suppliers with verifiable carbon data and IATF 16949 / EN 15088 / ISO 9001 as applicable to your segment. Run sample orders through PPAP or equivalent quality gate. Establish commercial terms with an index-linked price formula tied to EPD or LME + premium. Lock in 12-month framework agreements with at least two qualified suppliers. The 2027 extrusion market will reward buyers who locked in qualified alternative supply in 2026. It will punish buyers who signed flat-price contracts without an index clause. The diagnostic — five questions, save this When evaluating any aluminium extrusion supplier, ask these five questions: What is your primary smelter source? If the answer is "various" or "we do not track," find another supplier. Do you have a published EPD for 6063 extrusion billet? If no, your CBAM exposure is the default value. What is your tolerance capability, and what is your measured Cpk? ±0.2 mm is standard. Anything tighter is precision work and priced accordingly. What is your IATF 16949 status? Required for automotive-adjacent, expected for industrial automation. What is your typical lead time for a custom die? Standard is 8 to 16 weeks. Faster means they are running hot. If a supplier passes all five, they are qualified for serious sourcing. If they fail any, you have a specific question to answer before placing the next order. What this means through 2030 Europe will be importing more aluminium — not less — for the rest of the decade. The supply map is rotating away from the Middle East and toward China, Canada, Brazil, and a small set of qualified non-European extrusion mills with verifiable carbon data. The CBAM framework will tighten every year through 2027 and beyond. The billet premium will not return to pre-2026 norms. The buyers who will do well in this market are the ones who treat this as a structural shift rather than a temporary disruption. They qualify multiple suppliers. They put index clauses on every contract. They collect EPDs. They audit, then audit again. The buyers who will not do well are the ones who signed flat-price contracts in Q4 2026 and are now trying to renegotiate from a position of dependency. About the Author Jason Yang is the founder of LinkedAlu, an aluminium extrusion manufacturer based in China with 21 years of operating history and 100,000 tonnes of annual production capacity. LinkedAlu supplies 6xxx-series extrusions to industrial automation, automotive, solar PV, semiconductor equipment, and packaging machinery customers across Europe and Asia. The views in this article are based on publicly reported industry data and the author's direct experience supplying European buyers through the 2021–2026 supply disruptions. Sources and references European Aluminium industry association, annual statistics Fastmarkets International Aluminium Conference, Budapest, September 2026 AL Circle trade data, Germany extrusion market Q2 2026 Kpler Insight, European natural gas outlook 2026 ING commodity research, Mozal closure analysis (December 2025) Reuters, Bloomberg, Mining Weekly, SANA (Syr Arab News Agency), Eurostat Q1 2026 energy imports Hydro ASA quarterly reports (Qatalum status) Constellium investor disclosures European Commission CBAM regulation (EU 2023/956) and 15 September 2026 parliamentary vote on CBAM expansion IEA Oil Market Report, March 2026 coordinated stock release U.S. Geological Survey, Mineral Commodity Summaries 2026 (aluminium) Wood Mackenzie European gas storage winter 2026/27 forecast (via Rigzone, 10 September 2026)

=== The Structural Break in Global Aluminum ===
URL: https://www.linkedalu.com/insights/the-structural-break-in-global-aluminum.html
Published: 2026-09-14
The Assumption That Ran the Global Aluminum Market for Twenty Years For two decades the global aluminum market ran on a quiet assumption: when demand rose, China would add capacity. That assumption is gone. China's primary aluminum output has effectively hit its 45 million-tonne regulatory ceiling, a cap introduced in 2017 to manage domestic carbon intensity, and 2025 production ran at roughly 44.9 million tonnes. There is no room left for incremental supply from the world's largest producer. What remains is a market in which the gap between structural supply growth and structural demand growth is no longer a forecast. It is open in real time. That matters to anyone who buys, specifies or machines aluminum. It moves the price floor, stretches the lead-time conversation and changes the negotiation posture of every extrusion enquiry. The structural break has four supply-side causes and three demand-side drivers, and they are firing simultaneously. Four Supply Constraints Firing at Once China's capacity ceiling. The 45 million-tonne cap was introduced in 2017 to manage domestic carbon intensity. With 2025 output at roughly 44.9 million tonnes, the world's largest producer has no headroom left to answer a demand pull. Guinea's export cap signal. Guinea is the upstream supplier that feeds most of China's alumina refineries, and it is now signalling an export cap of its own - a second, upstream constraint on the same supply chain. Sanctions on Rusal. Rusal accounts for roughly 6% of global supply and has been progressively cut off from Western shipping and alumina feedstock by successive EU and US sanctions. The February 2026 Gulf curtailment. The Gulf's largest single-site smelter curtailed output in February 2026 after regional energy infrastructure was hit. Read individually, each of these is a disruption. Read together, they describe a supply system with no shock absorber left in it. There is no large idle smelting fleet waiting to be switched on, and no single jurisdiction that can replace what is being removed. Demand Is Accelerating on Three Fronts at Once Demand is not waiting for supply to catch up. It is accelerating on three fronts at once: electric vehicles, solar energy, and the structural substitution of copper by aluminum in power cables, busbars and HVAC heat exchangers. The scale of the requirement is documented. The IEA estimates that net-zero by 2050 requires a 40% increase in primary aluminum production from today's levels. CRU projects global demand growing from 86.2 million tonnes in 2020 to roughly 119.5 million tonnes by 2030. Set those figures against a supply base that is flat at best, and the direction of travel is not ambiguous. Copper Substitution in Vehicle Wiring The substitution story is worth isolating because it is the least intuitive and the most quantifiable. China's NEV low-voltage harness aluminum-content rate reached 68% in 2025, according to China Electric Power Research Institute data. High-voltage connectors and battery-pack busbars are scheduled for production-intent adoption by late 2026, with per-vehicle copper savings of roughly 10 kg. Across a global vehicle production base of roughly 30 million NEVs per year, single-digit kilogram copper savings per vehicle translate into hundreds of thousands of tonnes of incremental aluminum demand - demand that the constrained upstream supply chain must now find a way to serve. What the Structural Break Changes for Buyers Constraint What it changes for extrusion buyers China's 45 Mt ceiling No capacity release to cool a price spike. Quotation validity windows shorten and price floors rise. Guinea export cap signal Alumina feedstock risk feeds straight into billet availability. Rusal sanctions Origin diversity and traceability move from a compliance detail to a supply question. Gulf curtailment Single-site concentration risk is now a live planning assumption rather than a theoretical one. EV, solar and copper substitution Alloy and profile demand competes with high-value applications for the same billet. How Procurement Teams Should Respond Treat the price floor as structural, not cyclical. Planning that assumes a return to the old range simply defers the problem. Shorten the loop between quote and order. A conventional long validity period is a risk the supplier now carries, and it is priced accordingly. Lock alloy and temper early. Confirm 6063-T5, 6061-T6 or 6005A-T6 requirements up front so tooling and billet sourcing start on the correct assumption. Design for material efficiency. Re-examine wall thickness and section geometry with the extruder rather than accepting a legacy design that was never optimized for today's metal cost. Diversify origin without fragmenting quality. Multiple billet sources are sensible; multiple finishing standards are not. The Bottom Line The structural break is not a trading event that will resolve itself next quarter. It is the point at which two decades of elastic supply stopped being elastic. Buyers who plan around that reality - with realistic price bands, shorter quotation cycles and better-engineered profiles - will spend less energy absorbing volatility than buyers who keep waiting for the old market to return.

=== Tariffs, R&D, and the Myth of the Fragile Chinese Factory ===
URL: https://www.linkedalu.com/insights/tariffs-rd-and-the-myth-of-the-fragile-chinese-factory.html
Published: 2026-08-18
Four Headlines, One Week, Seemingly Contradictory Stories Four stories from three of the world's most influential business publications landed in the same week, and read separately they appear to contradict one another. The Wall Street Journal reported that China's economy has holes. The New York Times reported that companies are moving production back to China. Nikkei reported that China now leads the world in enterprise R&D spending. The Wall Street Journal also reported that China's tech sector is sprinting ahead. Read together, they tell a far more interesting story - and for anyone buying from, selling to, or competing with Chinese manufacturers, that story matters more than any single headline. The Two-Speed Economy The Wall Street Journal frames China as a two-speed economy. One speed is high-tech manufacturing: electric vehicles, batteries, solar equipment, industrial automation and AI-related hardware. These sectors are expanding fast, gaining global market share and driving export growth. The other speed is domestic: property markets struggling, consumer confidence weak, local government debt unresolved. That framing is fair, and any honest analysis has to acknowledge it. What gets less attention is what actually drives the high-tech engine. It is not running on government subsidies alone. It is running on something deeper. The R&D Figure Nobody Expected Nikkei reported that China's R&D spending reached $615 billion, taking the global lead. The figure is striking, but the critical detail is the funding source: the dominant share comes from commercial enterprises - companies reinvesting their own revenue into research and development - not from state grants. Why Enterprise-Funded R&D Changes the Competitive Picture A government-funded R&D program is a policy decision. Enterprise-funded R&D is a survival behavior. It means thousands of manufacturers are independently betting their own capital that better processes, tighter tolerances and superior surface finishes will win global market share. A buyer is then not competing against a subsidy. They are dealing with a supplier that reinvests profit to get better every quarter. Tariffs Versus Ecosystem Density: Why Production Moves Back The New York Times reported a trend that runs against the prevailing political narrative: several multinational firms that moved production out of China to avoid tariffs are now shifting it back. The logic is not sentimental. It is arithmetic. Tariffs added direct costs, but the alternatives introduced hidden ones: Fragmented local supplier networks. Extended lead times for specialized alloy tooling and components. Quality consistency challenges across multiple sites. High overhead from managing production across several jurisdictions. When procurement teams calculated the true total cost of ownership - factoring in scrap rates, lead-time reliability and engineering support - China frequently came out ahead even with tariffs applied. A tariff is an explicit tax. A fragmented supply chain is an implicit tax paid in time, defects and lost management focus. How High-Tech Precision Spills Over into Everyday Products The second Wall Street Journal piece treats technological progress and broader economic health as separate tracks. In industrial manufacturing they share the exact same track. The advanced factories producing EV battery enclosures and solar infrastructure rely on the same core ecosystem that extrudes architectural frames, CNC-machined housings and heat sinks. Process knowledge diffuses fast across sectors. A machining shop that has mastered 5-micron tolerances on automotive components applies the same discipline to standard industrial profiles. An extrusion plant that developed thin-wall structural profiles for solar frames transfers that metallurgy into commercial window systems. Capability is not siloed by product category; it is a plant-wide habit. What This Means for Global Buyers At Linkedalu we extrude aluminum profiles and machine them into finished components for customers in the solar, industrial automation, automotive and architectural sectors, operating directly inside that competitive ecosystem. In practice that translates into three working factors. Practical R&D. Not a theoretical line item: the tooling redesign that removed chatter marks on a custom profile, the process refinement that held tighter tolerances on a solar mounting rail, the die-steel trial that extended tool life by 40%. These improvements are funded from internal margin because the next order will demand higher precision. Supply chain consolidation. Tariffs changed the arithmetic but not the fundamentals of manufacturing density. Customers who attempted multi-country sourcing often returned, because managing one integrated supplier that holds plus or minus 0.1 mm machining tolerances is far more efficient than coordinating three vendors across three countries. Survival through capability. The Chinese factories that survived trade friction did not survive by being the cheapest. They survived on better tolerances, superior anodizing and powder finishes, complete CMM inspection reports and responsive English-language engineering support. The Grounded Reality Chinese manufacturing is not a monolith. Capabilities vary widely, and structural adjustments in property and local debt will take years to resolve. But the global supply chain story does not hinge on the domestic property market. It hinges on whether factories can consistently deliver high-precision products that global industries require. The manufacturers still investing, improving and shipping are not fragile operations leaning on subsidies. They are lean, capable organisations that have learned to compete on engineering quality, process control and total cost efficiency. A tariff line in a spreadsheet does not measure any of that.

=== Your "Cheap Chinese Aluminum" Stereotype Is 10 Years Out of Date: How Automation Is Rewriting the Rules of Extrusion Quality ===
URL: https://www.linkedalu.com/insights/your-cheap-chinese-aluminum-stereotype-is-10-years-out-of-date-how-automation-is-rewriting-the-rules-of-extrusion-quality.html
Published: 2026-07-22
What a Modern Extrusion Plant Actually Looks Like If you still picture an overseas aluminum extrusion plant as a dim shed full of operators yanking hot profiles out of a rusty press with pliers, you are long overdue for an update. That factory certainly existed, and it probably still does somewhere. But the plants supplying the global solar, electric vehicle and industrial automation sectors today look more like data centers with a smelter attached. Automation is not replacing people. It is replacing inconsistency. The Questions Every Procurement Director Asks If you have sourced extruded aluminum globally, you have probably run through these questions during risk assessment: Is the structural quality actually consistent, or am I rolling the dice on every container? What happens to dimensional tracking if an experienced shift supervisor leaves the line? Are we merely buying cheap labor that will evaporate the moment local wages rise? These are not unfair concerns; they are born from decades of supply chain history. The answer today is fundamentally different from ten years ago, and the driving force is deep-floor automation. The Real Enemy Was Never Labor. It Was Variation. There is a lazy narrative that factories only compete on low hourly wages. Localised cost advantages exist, but that gap has been closing for a decade. What destroys a buyer's margin is not the hourly rate of the technician operating the saw. It is what happens when an operator has an off day. If a billet is loaded into the press slightly cooler than specification, or the ram speed is pushed a touch too fast to hit a shift quota, the resulting profile may look visually flawless. But the internal grain structure has been altered. Six months later, a structural PV frame installed in a high-wind environment develops a stress fracture that traces back to that single inconsistent batch. The real threat to your supply chain is metallurgical and dimensional variation - and variation is exactly what automation is engineered to eliminate. Three Areas Where Automation Changed the Metric 1. The Extrusion Press: From Human Feel to Closed-Loop Feedback The old way relied entirely on intuition. An operator judged billet temperature by the color of its incandescent glow and adjusted ram speed by watching how the profile emerged onto the run-out table. A master operator could produce excellent profiles; a tired or distracted one could produce hidden scrap that passed visual checks and failed a tensile test. Today, integrated thermocouples and infrared pyrometers monitor billet temperature to within plus or minus 5 degrees Celsius. Closed-loop controllers adjust induction heating power in real time, and press speed is dynamically modulated based on continuous exit-temperature readings. The result is that every meter of profile leaving the press is processed under effectively identical thermal and mechanical conditions. Tensile strength, yield strength and elongation stay steady across the batch - not because the operator is a genius, but because the control loop will not allow the equipment to deviate. 2. CNC Machining Centers: The Death of Close Enough Drilling mounting slots or milling precision features used to be a manual operation involving local jigs, hand drills and measuring tapes. Positional tolerances hovered around plus or minus 0.5 mm on a good day. When those parts reached the field, installers found the holes did not align with the tracking rails, force-drilled new ones on site, scratched the protective anodizing and voided the structural warranty. That workflow now runs through automated multi-axis CNC machining centers. Six-meter extruded bars feed automatically into the enclosure, where multiple spindles drill, tap and mill in a single continuous pass. Hole position accuracy is held strictly to plus or minus 0.15 mm, batch after batch. The machine does not suffer fatigue after lunch and cannot take shortcuts. The operators who once held manual drills are now technicians programming the CNC arrays and managing precision tooling lifecycles. 3. AI Vision Systems: Inspection That Never Blinks For decades the final barrier against surface defects on anodized or powder-coated profiles was an inspector at a light table, watching metal roll past. After a long shift, human attention drifts. A faint die line, a microscopic scratch or a localised spot of oxidation slips by unnoticed - until it catches the sunlight on a high-rise facade. AI-driven surface inspection vision arrays do not drift. High-speed, high-resolution cameras scan every millimeter of surface, and machine-learning classifiers trained on thousands of surface defect profiles instantly flag scratches, pickup and color variation. The system logs the exact coordinate, length and severity of each anomaly, generating a defect map for the entire production lot. Defects are caught and isolated on the factory floor, long before they can reach an ocean container. Structural Process Data as a Competitive Advantage Automation matters to a buyer not because the machines are impressive, but because of what they produce besides metal: process data. A closed-loop press, a CNC cell and a vision array together create a lot-level record of the thermal, dimensional and surface conditions that made the part. That record is what makes a claim defensible and a reorder repeatable. Process stage Manual-era capability Automated capability Billet heating control Judged by glow color and operator feel Thermocouples and infrared pyrometers holding within plus or minus 5 degrees Celsius Press speed control Adjusted by eye on the run-out table Closed-loop modulation from continuous exit-temperature readings Machining position Hand drills, jigs and tapes, around plus or minus 0.5 mm Multi-axis CNC on six-meter bars, held to plus or minus 0.15 mm Surface inspection Visual check at a light table AI vision arrays with logged defect coordinates and severity What to Ask Any Supplier, Anywhere How is billet temperature controlled, and what is the documented tolerance? Is press speed set by operator judgement or by a closed-loop controller? What positional tolerance is guaranteed on machined features, and is it verified per lot? How is surface quality inspected, and can you supply the defect data for my last shipment? Can you provide traceable inspection reports, not just a certificate of conformity? The Point The cheap-labor stereotype describes a supply chain that genuinely existed. It no longer describes the plants winning solar, EV and automation business, because those customers are not buying hours - they are buying repeatability. The factories that invested in closed-loop control and automated inspection did it precisely because sophisticated buyers stopped rewarding anything else.

=== The New Geography of Aluminum: Four Events in July 2026 That Just Redrew the Map ===
URL: https://www.linkedalu.com/insights/the-new-geography-of-aluminum-four-events-in-july-2026-that-just-redrew-the-map.html
Published: 2026-07-15
Four Events That Read as One Story In the first ten days of July 2026, four things happened that - read separately - look like standard industry news. A corporate acquisition. A government-backed project announcement. A plant closure. A feasibility study. Read together, they are not separate events at all. They are a single story about where aluminum will come from in the next decade, who will control it, and what it will cost. July 1: Alcoa Buys South32's Aluminum Business for $5.6 Billion Alcoa agreed to acquire the bulk of South32's aluminum operations in a deal valued at $5.6 billion: $3.1 billion in cash, $1 billion in stock, and up to $750 million in contingent payments tied to aluminum prices through 2030. What Alcoa gets is significant. The Hillside smelter in South Africa, the largest in the southern hemisphere with 718,000 tonnes of annual capacity. The Worsley alumina refinery in Australia. A package of Brazilian assets including the MRN bauxite mine, an alumina refinery and a smelter. The deal is expected to close by June 2027. What South32 is still trying to sell is the Mozal smelter in Mozambique, which has been idle since early 2026 and remains without a buyer. Why Ownership Matters More Than the Price Tag The significance is not just the price. It is who bought it. A Pittsburgh-based company is now the controlling force behind Africa's largest primary aluminum asset. That is a structural shift in ownership and, eventually, in how that metal flows to market. July 9: EGA and Colombia Plan South America's First Aluminum Smelter Emirates Global Aluminum, one of the world's largest producers, signed an agreement with NEO Aluminio Colombia to develop the Galtco green aluminum conversion plant in northwestern Colombia. Planned capacity is 540,000 tonnes per year, and the power source is hydropower. If it proceeds, it would be the first primary aluminum smelter in South America - a continent that has historically been an aluminum importer rather than a producer. The project is in development, not under construction. But the partnership is real and the logic is sound: Colombia has abundant hydropower, Atlantic and Pacific port access, and a growing appetite for industrial investment. EGA brings the smelting technology and the customer relationships. Buyers should treat the capacity as a late-decade factor, not a 2027 one. Africa: Egypt Rises While Mozambique Goes Quiet Egypt is advancing its mineral localisation agenda, including a $900 million Trafigura-linked project, while the Mozal shutdown in Mozambique removes an established southern African supply node from the market. The two moves point in opposite directions and land in the same region, which is precisely why the map now reads differently than it did a year ago. For an extrusion plant buying billet or ingot, regional supply nodes are the ones that respond fastest to a disruption: they ship short, they re-quote quickly, and their loss is felt in weeks rather than quarters. What This Means for Extrusion Buyers Event Near-term read for buyers Alcoa acquires South32's aluminum business ($5.6bn) Consolidation under a single owner changes how that metal is marketed and contracted; expect longer-term offtake thinking. Mozal remains idle with no buyer A former supply node is out of the picture and may not return quickly. Colombia's Galtco project (540,000 t/y, hydropower) A future low-carbon origin, but years away. Useful for 2030 planning, not next season's billet. Egypt's mineral localisation and the Trafigura project New mid-stream capacity that may reduce regional import dependence over time. Qualify more than one origin before you need to, so switching is a decision rather than a scramble. Extend contract horizons selectively where consolidation has changed who your counterparty effectively is. Strengthen traceability now, because origin claims will be audited more often as supply fragments. Budget for premium volatility as physical metal moves between more owners and fewer, larger trading relationships. The Through-Line None of these four events was announced as part of a plan. They were independent commercial and policy decisions made within ten days. That is exactly what makes them worth reading together: they show a supply chain remaking itself in real time, from the bauxite mine through the alumina refinery to the smelter gate. Ownership, energy cost, carbon intensity and political risk are all being re-priced at once, and the metal that reaches an extrusion press in 2030 will come from a materially different set of assets than the metal arriving today. Buyers who treat the aluminum map as static will keep being surprised by it, and surprise is the most expensive input in any supply chain.

=== Citi's "Most Bullish Aluminum Forecast Ever" Explained: Navigating the New Era of Structural Scarcity ===
URL: https://www.linkedalu.com/insights/citis-most-bullish-aluminum-forecast-ever-explained-navigating-the-new-era-of-structural-scarcity.html
Published: 2026-05-28
What Citi Actually Said Global banking group Citigroup recently declared that the aluminum market is entering its most bullish cycle in over 50 years. In its published forecast, Citi projects that London Metal Exchange aluminum prices will climb swiftly to $4,000 per tonne in the short term, with substantial further upside heading into 2027. Treat that as a forecast from Citi's analysts, not as a settled fact - but the supply-side evidence behind it deserves attention, because it is largely physical rather than financial. The Three Pillars of Citi's Case Citi's model rests on three supply-side data points that together describe a deep structural deficit: A three-million-tonne supply severance. According to Citi, ongoing geopolitical conflict in the Middle East has caused historic supply chain ruptures, and the market faces an immediate loss of more than 3 million tonnes of global aluminum supply - a scale of disruption rarely seen in modern metallurgy. Inventories at a 55-year low. LME on-warrant registered stocks have plunged by a third this year to roughly 339,000 tonnes. Crucially, shadow stocks - unregistered metal stored off-exchange - have hit their lowest levels since tracking began in 2020. The market's inventory buffer is gone. Zero global idle capacity. Idled smelting capacity worldwide is almost entirely depleted. Even as prices rocket upward, producers cannot simply switch on closed pots to relieve the squeeze. Read together, those three points explain why the bullish case is described as structural rather than cyclical. A cyclical squeeze is relieved by restarting capacity. A structural squeeze has nothing left to restart. The Disconnect: Paper Price Versus Physical Premiums As of late May 2026, LME three-month aluminum traded near $3,630 per tonne. It had risen roughly 14% since recent geopolitical escalations, yet it had not broken past the historical peaks seen in 2022. Analysts quoted in industry coverage note that paper futures have failed to register the tectonic shifts shaking the physical supply chain. For B2B buyers, the real tension is flashing in physical spot premiums rather than in the exchange ticker: Physical signal Reading as of late May 2026 LME cash-to-three-month premium $80 per tonne - the highest since 2007, signalling profound immediate scarcity Japanese port premiums (CIF) Doubled to $316 per tonne, with Q2 contract talks reaching an 11-year high of $350 per tonne Rotterdam duty-paid premiums Up 58% since March 2026 Rotterdam aluminum billet premiums Surged sharply, reflecting competition for semi-finished metal rather than primary ingot alone The billet line is the one extruders feel first. Primary metal can be sourced and shipped; billet must be cast to the right diameter and alloy for a specific press and die. When billet premiums surge, the constraint has moved from the smelter to the semi-finished supply chain that extrusion plants actually buy from. What Structural Scarcity Does to Extrusion Buyers If Citi's read is broadly right, the consequences for profile buyers are practical rather than theoretical. Quotation validity becomes a cost line. A supplier holding a fixed price for a long window is carrying real metal risk, and it will be priced in one way or another. Alloy discipline pays. Buying 6063-T5 where a higher-cost alloy is not required, and confirming temper and tolerance up front, avoids over-specifying metal. Wall thickness and section design deserve a second look. A profile optimized for the previous price decade is rarely optimized for this one. Billet access outperforms ingot access. The ability to secure cast billet, not just metal exposure, is what keeps a press running. Longer planning horizons beat reactive buying. In a tight physical market, the buyer who plans two quarters out negotiates from a stronger position. Reading Citi Correctly Forecasts are not outcomes. Citi's published projections may prove too bullish, and a demand shock or a faster-than-expected capacity restart elsewhere would change the arithmetic. It is also worth noting what Citi is not saying: that aluminum becomes unavailable, or that buyers should panic-purchase. The call is about price and tightness, not about absence of metal. The defensible conclusion for an industrial buyer is narrower and more useful. The supply system has very little slack, the physical premiums are telling a harder story than the futures curve, and procurement plans built on assumptions of abundant, cheap, quickly replaceable metal are now the risky ones. Plan for the floor, and let the ceiling look after itself.

=== Navigating the 2026 Aluminum Surge: Resilience, Technical Standards, and the New Global Supply Dynamic ===
URL: https://www.linkedalu.com/insights/navigating-the-2026-aluminum-surge-resilience-technical-standards-and-the-new-global-supply-dynamic.html
Published: 2026-05-20
Two Forces, One Divergence The global aluminum landscape is experiencing a profound structural shift. According to recent market analysis from Bloomberg, China's primary aluminum output has hit historic highs, fuelled by an influx of raw materials and optimized smelting margins. Yet this production surge arrives at a time when traditional real estate demand is cooling, creating a market divergence: a large volume of high-grade aluminum is available to support the rapid acceleration of international green energy and modern architectural infrastructure. For global procurement managers, industrial engineers and construction developers, navigating this macro environment demands attention to two core pillars: supply chain reliability and uncompromising international technical compliance. Neither is optional, and neither is a substitute for the other. Where Demand Actually Went While traditional building sectors see a temporary slowdown, the paradigm of aluminum consumption has fundamentally changed. The modern economy is driven by high-tech electrification and sustainable design, shifting demand toward specialized, high-performance extrusions: Solar and renewable infrastructure. High-durability structural frames and mounting profiles engineered to survive extreme environmental wear. Next-generation automotive and EVs. Lightweight, high-tensile components optimized to maximize battery efficiency and structural safety. Advanced architectural facades. High-performance, energy-efficient curtain wall systems that define sustainable modern skylines. Each of these three demand streams imposes requirements that a generic profile catalog cannot meet. A solar mounting rail is judged on decades of corrosion and mechanical loading performance. A battery enclosure component is judged on dimensional repeatability and alloy consistency. A curtain wall mullion is judged on thermal performance, surface quality and sightline precision. The aluminum is similar; the engineering is not. Supply Reliability Is Now a Technical Question In a market saturated with raw volume, true value lies in precision engineering and technical authority. Buyers who treat supply resilience as purely a commercial exercise - more suppliers, more buffer stock - tend to rediscover the same problem: inconsistent tolerances across vendors create scrap, rework and field failures that no safety stock can absorb. Standards and Compliance For international buyers seeking to mitigate risk, the practical standard is that supply is always backed by recognisable benchmarks. Every metric tonne of extruded profile should comply with ASTM (American) and EN (European) standards where the project specifies them, with alloy and temper declared and verifiable - typically 6063-T5 for architectural and solar profiles, or 6061-T6 and 6005A-T6 where higher mechanical properties are required. Advanced surface treatments matter just as much. Anodizing and powder coating are not cosmetic finishes; they are the corrosion-control system for a facade or a mounting frame that will be exposed for decades. Thickness, adhesion and color consistency should be documented, not assumed. A Practical Checklist for Procurement Managers Question What a good answer looks like Which standards govern the profile? Named ASTM or EN standard, with alloy and temper declared per profile. How is dimensional consistency demonstrated? Inspection records tied to the production lot, not to a sample. How is surface finish controlled? Documented coating or anodizing thickness and adhesion testing. Who owns the technical conversation? Engineering support that can respond in the buyer's language and timezone. Why Integrated Manufacturing Reduces Risk Extrusion, heat treatment, finishing and machining performed under one quality system remove the transfer points where tolerances drift and responsibility becomes ambiguous. When a deep-processed component arrives ready to assemble, the buyer inherits one specification and one accountable supplier instead of a chain of three. That integration is also what allows a supplier to respond to design changes. When aluminum costs are elevated, the cheapest engineering improvement is often a redesign - thinner walls, a more efficient section, less machining allowance - and it can only be executed by someone who controls the die, the press and the machining center. A trading intermediary can re-quote a price; it cannot re-engineer a section, test the new die and hold the tolerance on the finished part. The Bottom Line The 2026 surge is not only a price story. It is a reallocation of aluminum from legacy construction demand into electrification, renewables and modern facades, and the metal is moving into applications that are far less tolerant of a bad lot. The buyers who navigate it well will be those who pair commercial resilience with rigorous technical compliance, and who choose suppliers able to evidence both.

=== 2026 Aluminum Storm: Navigating Geopolitical Turmoil and Record-High Costs ===
URL: https://www.linkedalu.com/insights/2026-aluminum-storm-navigating-geopolitical-turmoil-and-record-high-costs.html
Published: 2026-05-12
The Most Volatile Phase in Decades The global aluminum market has entered its most volatile phase in decades. As of May 2026, LME aluminum prices have surged toward $3,600 per tonne - a 35% year-on-year increase. Driven by the closure of the Strait of Hormuz and aggressive new tariff regimes, the industry is shifting from a cost-first model to a security-first procurement strategy. For anyone buying extruded profiles, that shift changes the questions worth asking. Price still matters, but continuity, origin and quoting mechanics now decide whether a project actually ships. The Perfect Storm: Why Prices Are Rising The current price action is a structural shift caused by three converging forces. Geopolitical chokepoints. The closure of the Strait of Hormuz has paralysed nearly 9% of global aluminum supply, causing an immediate liquidity crunch for high-quality primary aluminum. The tariff effect. With a 50% tariff looming under 2025 trade policies, the US Midwest Premium has surpassed $1 per pound for the first time in history, placing an immense burden on downstream manufacturers. Manufacturing under pressure. Global manufacturers including Ford and Molson Coors have reported record-high input costs, forcing a ripple effect across the entire architectural aluminum sector. Two of those three forces are policy-driven and therefore reversible on a political timetable. The third - a physical chokepoint affecting roughly one eleventh of world supply - is not something a buyer can wait out with a spreadsheet. What the Numbers Say About 2026 and 2027 Period Market view May 2026 spot LME aluminum near $3,600 per tonne, up 35% year on year 2026 annual average Prices expected to remain elevated, averaging around $3,400 per tonne 2027 projection A soft landing toward $3,200 per tonne as supply chains reroute and the market adjusts to the new tariff landscape The forecast shape matters as much as the levels. Even the softer 2027 view sits far above the range buyers were planning against three years ago. A soft landing is not a return to the old normal. Why Security-First Replaced Cost-First When spot markets move by the hour, the cheapest quote on Monday can be the most expensive decision by Thursday. Procurement teams that optimized purely on unit price have discovered the cost of the alternative: re-quoting mid-project, absorbing metal risk they cannot hedge, and explaining schedule slips to customers. The practical response is not to abandon cost discipline. It is to price continuity explicitly and to choose suppliers whose commercial mechanics are transparent enough to plan around. Quoting Discipline: The Weekly Fixed Quote System In a market where prices can fluctuate by the hour, Linkedalu Metal Group operates a weekly fixed quote system designed to give buyers predictability: The Monday quote. Every Monday a fixed price is issued for aluminum profiles based on current market data. Weekly validity. That price remains valid until Friday, allowing buyers to bid on projects and manage cash flow with confidence. The stability trigger. A quote is only adjusted mid-week if the cost of aluminum ingots fluctuates by more than US$45 per tonne. Minor market noise is absorbed by the supplier rather than passed through. Engineering for Cost Efficiency Above $3,500 Per Tonne When aluminum exceeds $3,500 per tonne, every gram matters. Engineering support should help redesign profiles - leveraging the superior strength-to-weight ratio of 6063-T5 - to reduce wall thickness without compromising structural integrity. Done properly, this is a technical exercise with inspection data behind it, not a cosmetic thinning of the section. Supply Continuity With the new tariff landscape, the origin of aluminum is critical. Maintaining a strategic raw material buffer supports a 15 to 25 day lead time, so projects stay on schedule even when global spot markets are tight. That buffer is a working capital decision, and it is one of the clearest signals of whether a supplier intends to be a long-term partner. What Buyers Should Do This Quarter Ask every supplier how their quote validity works and what triggers a mid-week revision. Confirm the alloy and temper you are actually being quoted, and stop paying for properties the application does not need. Re-examine wall thickness and section geometry with your extruder while metal is expensive. Verify lead-time commitments in writing, and ask what raw material buffer stands behind them. Diversify origin, but consolidate finishing standards so quality does not fragment with sourcing. Stability as a Deliverable Twenty years of extrusion experience teaches one durable lesson: volatility is inevitable and unmanaged volatility is optional. Turning market chaos into a manageable business variable - through transparent weekly pricing and genuine engineering support - is a better answer than a daily price list nobody can plan against. Companies that partner with transparent, stable-pricing suppliers today will be the ones best positioned when prices stabilize in 2027.

=== Why Aluminum Extrusion Quotes Differ ===
URL: https://www.linkedalu.com/knowledge/why-aluminum-extrusion-quotes-differ.html
Published: 2026-10-22
Two quotes for the same drawing rarely agree. The gap sits in the billet basis behind the price, the wall actually delivered — 0.8 mm is the floor here, a groove is held to ±0.1 mm — the finish class, AA10 against AA15, and what the quotation leaves out: die, machining, packing, documents. We quote FOB Shenzhen or Guangzhou against a stated billet date, 500 kg minimum per profile. Most buyers compare the number at the bottom. The useful comparison is the four items in the table below, because each one is a decision the supplier made before quoting — and each one shows up later, in assembly or in a claim. Where the money moves What the cheaper quote does What it costs you later Billet basis Prices against an older date or a lower regional basis The number moves at order confirmation Wall and tolerance Runs the lower half of the permitted tolerance Grooves and hinge screws suffer first Finish specification AA10 instead of AA15, 60 µm instead of 80 µm Colour drifts, edges wear through Scope Leaves out die, machining, packing or documents The invoice at shipment is the real price What moves the price before the metal is cut? Aluminum is priced in two layers: the billet and the conversion. The billet follows a published market — LME plus a regional premium — and in China several bases are published side by side: Nanhai Lingtong, Shanghai SMM and Changjiang. They are not the same number on the same day, and each mill prices off the one its region settles on. Guangdong converters, including this plant, quote mostly against Nanhai Lingtong, which is the highest of the three. That is the plain reason a Foshan quotation runs above a quotation from an inland province for an identical section: the input is dearer, not the margin. Foshan is also where extrusion started in China, and the whole chain — die shop, presses, anodizing, powder line, machining — still sits inside a short radius, worked by people who have run these lines for decades. The premium buys process control, not a logo. Above the billet, three variables move the conversion charge: Alloy. 6063 is the volume grade and the cheapest to extrude; 6061 and 6082 run slower and cost more; 6463 costs more again because it is made for bright anodizing. The differences in strength and finish are set out in our 6063 versus 6061 comparison. Temper. T6 adds a heat-treatment step over T5 and is quoted above it; T4 is used where the part is formed after extrusion. Order size. A container and a few tonnes are two different quotes, and often two different packing methods. Setup, die amortisation and finishing batch charges do not shrink with the order. Wall thickness belongs on this list too. A 0.8 mm wall runs slower through the press, wears the die faster and rejects more often than a 2 mm wall, so the conversion charge per kilogram rises even though each metre weighs less. Why does a lower price often mean a thinner wall? Dimensional tolerances are bands, not single values. GB/T 5237 high precision defines a permitted range for every dimension, and a supplier can sit anywhere inside it. A quote built on the bottom of the band is a legitimate quote — and a lighter profile. The failure mode is predictable. A groove specified to take an 18 mm panel is held to ±0.1 mm at this plant; a groove that arrives 0.2 mm off will not accept the panel after anodizing, or lets it rattle once it is in. Neither shows on the drawing. Around a hinge, two or three threads in a 0.9 mm wall will pull out after a season of use, while the same hinge in a 1.4 mm wall holds. The sections most exposed to this are the cabinet and wardrobe profiles covered in furniture and cabinet profiles. You can check this without a laboratory: measure the same dimension at four points around one section, then repeat on three sections from different bundles. A single thin reading may be a burr; a systematic shortfall across twelve readings is the specification the supplier actually ran. Wall thickness checked on the factory floor: four readings per section, three sections per bundle. Thin walls are a capability here, not a discount. The floor is 0.8 mm, and on sections up to a 540 mm circumscribed circle the wall is set by what the part has to do — screw purchase, groove stiffness, dent resistance — not by what makes the quote look better. Where does the finish change both price and risk? Anodizing is sold by class. AA10 puts about 10 µm on each face, AA15 about 15 µm, and the second costs more because the line runs slower. On a vertical face that nobody touches, AA10 is the sensible buy. On a door edge, a handle return or a hospital corridor, 15 µm is what keeps the metal from wearing through at the contact point. Finish Nominal build Where it is the right buy Anodized AA10 about 10 µm per face Indoor faces, little handling Anodized AA15 about 15 µm per face Handles, door edges, humid or coastal air Powder coat 60–80 µm Colour range, hiding fine die lines Colour is a separate axis. Silver — sandblasted, alkali-etched, glass bead or steel shot, coarse to fine — is the most forgiving. Champagne, bronze, black and gold are progressively harder, and the darker the tone, the harder the batch-to-batch match becomes. That is metallurgy and bath chemistry, not sales talk: dye concentration, bath temperature and the alloy batch all move the final shade. Powder coating builds far more film, typically 60–80 µm. It buys colour range and hiding power, and it costs you fit: a 70 µm coat closes an 18 mm groove by about 0.14 mm, while AA15 anodizing closes the same groove by about 0.03 mm. Decide the fit after finishing, not before. Film build on a powder-coated profile: the gauge reads 74, inside the 60–80 µm range specified for architectural work. Wood grain is a transfer film over a powder base coat. The film is printed, so pattern and tone vary between rolls; an identical repeat from lot to lot is not achievable, and any supplier who promises it is promising something the process does not deliver. A wood grain sample kept with its film reference and date. The approved sample, not the drawing, is the acceptance basis for a print pattern. For the chemistry behind these choices, see surface finishes compared. For the price question, the practical point is narrower: a quotation that does not state the anodizing class and the film build is not a comparable quotation. What does a cheap quote leave out? Four things, in the order they usually appear. The die. Tooling is a one-off cost that depends on section complexity and press size, so it is quoted per project rather than published. A quote that folds the die into the per-kilogram price hides how much of your money is tooling — and says nothing about who owns the die, where it is stored, or what happens if you move supplier. Machining. Hinge holes, handle cut-outs, mitre cuts and end milling are operations, not extrusion. At this plant they run in the same building as the press, which is why they can be quoted as part of the same order; a trader's quote often stops at the extruded bar. Packing. Export packing is specified per order: protection film, interleaving between profiles, end caps, and bundle labels that match the packing list. On a container the difference is a few dollars per tonne; in claims it is the difference between a clean delivery and a shipment of scratched anodized faces. Documents and cut lengths. A mill test certificate to GB/T 5237, a dimensional report on the critical dimensions and the anodizing class actually run are part of the delivery, not extras. Cut lengths matter too: there is no standard length here, profiles are cut to your list, a 20' container takes up to 5.85 m, a 40' takes 6.0 m and can carry two lengths, and cuts under 5 m carry a sawing charge. How do you judge quality before you pay? Four checks cover most of the risk, and none of them needs a lab. Check How to run it What passes Substrate Look at a cut face and a scratch; check hardness Bright, uniform grain; no dark speckle, no porosity Wall Four points per section, three sections per bundle Inside the drawing, no systematic shortfall Colour Compare against the sealed master sample outdoors, at about one metre No visible difference at that distance Coating Film build gauge; cross-hatch on a sample 60–80 µm powder, no bare spots, no lift-off Two failure modes deserve their own line. Sealing: anodizing that has not sealed properly corrodes from the surface, and it shows up months later as a chalky bloom or as adhesive left behind when the protective film is removed. If the film comes off with glue still on it, suspect sealing and packing moisture before you suspect the film. Adhesion: powder that lifts at a cross-hatch was either under-cured, applied too thin, or put on a substrate that should never have entered the line. That last point is the one buyers miss. Powder hides the substrate, so a supplier chasing a low price can run second-hand billet and hold the tolerance at the bottom of the band; the part looks right in the crate and fails in service. Incoming inspection of chemistry, hardness and appearance is the only place that gets caught. Colour acceptance is where a written standard saves an argument. At this plant the standard is visual: under outdoor natural light, at a viewing distance of about one metre, a difference that is not noticeable is acceptable. Dark anodized tones are judged by that rule, not against a laboratory number. Wood grain is judged against the approved sample, because it is a pattern, not a shade. What we cannot do We do not publish a price list. The billet moves daily, and a list would be wrong within a week; we quote against the billet basis and date in force when you ask. We quote FOB Shenzhen or Guangzhou and nothing else. Freight, insurance and duty are handled by your forwarder, and the conversation about landed cost belongs there rather than in our quotation. We do not run second-hand billet. If the application needs a lower price than virgin 6063 allows, the honest answer is a different section or a different finish, not a different substrate. We do not promise batch-identical wood grain, and we do not promise zero colour difference on dark anodizing. What we do promise is a sealed master sample, a batch number on every carton, and the one-metre rule in writing. What to send for a quote you can compare Six items make quotations comparable line for line: Section drawing — DXF, DWG or a dimensioned PDF. Alloy and temper, or the job the part has to do. Finish and film: anodizing class, powder colour reference, or mill finish. Quantity per profile, and whether the order is a full container or LCL. Destination port and terms. Packing requirement, if the profiles will be machined or handled on site. With those, the quotation can state the billet basis and date, the anodizing class, the die line separately, and what is included in packing — which is what makes two quotes comparable at all. FAQ Is aluminum extrusion priced per kilogram or per metre? Per kilogram. Metres convert through the theoretical weight of the section, so a quote per metre without the weight per metre is not checkable. Why is your price higher than another Chinese supplier's? Usually three reasons: the billet basis (Guangdong prices off Nanhai Lingtong, the highest of the Chinese bases), the wall actually run, and whether die, machining and export packing are inside the number. What is the one-metre colour rule? Under outdoor natural light, at about one metre, a shade difference that is not noticeable is accepted. It is the standard written into our order confirmation for dark anodized tones. Do you use second-hand billet? No. Incoming billet is checked for chemistry, hardness and appearance before it reaches a press; material that fails is rejected. Why can't wood grain match from batch to batch? It is a printed transfer film over a powder base coat. Ink, film roll and cure all vary slightly, so the approved sample is the reference rather than an exact repeat. What is included in your quotation? Extrusion, the specified finish, cutting to your list, export packing and the mill certificate. Die tooling and machining are shown separately so you can see what you are paying for. What is the minimum order? 500 kg per profile, whether the die is new or existing. A container can carry several profiles on one order. Reviewed 2026-10-22 · LinkedAlu extrudes in Foshan on 26 presses (500–5000 MT), 100,000 t/year since 2005, FOB Shenzhen or Guangzhou.

=== Aluminium Extrusion Tolerances ===
URL: https://www.linkedalu.com/knowledge/aluminium-extrusion-tolerances.html
Published: 2026-10-21
Short answer. Extrusion tolerances are held to GB/T 5237 high-precision class at our plant, with groove and slot dimensions controlled to ±0.1 mm and wall thickness from 0.8 mm. What decides whether a drawing is achievable is not one number: it is the section shape, the alloy and temper, the die, and which dimensions you mark as critical. What is toleranced How we hold it What you must put on the drawing Wall thickness From 0.8 mm, held per GB/T 5237 high-precision class Minimum wall and where it applies Groove and slot width ±0.1 mm on grooves cut for it Which groove is functional (glass, gasket, hinge) Overall section size GB/T 5237 high-precision class Circumscribed circle and critical faces Straightness and twist Per GB/T 5237 high-precision class, checked on the bench Length and how the profile is supported in service Cut length To your cut list Whether length is a fit dimension Machined features Per drawing, after extrusion Datum faces and hole position tolerance Groove and Slot Tolerance A groove that takes a gasket, a glass bead or a hinge is a fit dimension, so it gets its own tolerance: ±0.1 mm on grooves we cut for it. That number is only reachable when the die is built for that groove and the wall beside it is not a thin isolated tongue — a 0.9 mm tongue next to a groove will move during cooling regardless of what the drawing says. Two things follow for the drawing. Mark the functional groove and say what goes in it. Leave decorative grooves to the general GB/T 5237 class, because tightening everything raises die cost and press time without improving the fit. What Changes the Tolerance Section shape. Open sections with even wall distribution hold tolerance better than sections with long isolated tongues, deep narrow slots or large flat faces unsupported on one side. Alloy and temper. 6063-T5 is the easiest to hold on architectural and industrial sections. 6061 and 6082 are harder to extrude and move more in quenching, so a tight tolerance on 6082-T6 is a different conversation from the same tolerance on 6063-T5. Wall thickness. Below 1.0 mm the wall cools fast, the section twists more and the press runs slower. A 0.8 mm wall is achievable — we extrude from 0.8 mm — but it is the wall where tolerance and cost argue most. Die condition. A new die holds tolerance better than one at the end of its life. Die maintenance is part of tolerance, not a separate topic. Anodising and Coating Surface treatment adds thickness on the outside of the section. Anodising at AA10 and AA15 builds a film in the range that matters to a sliding fit or a press-fit insert; powder coating is thicker again. If a groove takes a gasket, or a hole takes a press-fit insert, the treatment thickness belongs on the drawing as a fit condition, not as a finish note. Practical order: tolerance the extrusion, state the finish and film thickness, then check the fit after finish. That order prevents a batch that measures correctly in mill finish and does not assemble after anodising. Twist, Straightness and Camber These three move with length, so they are quoted per length, not per profile. A 6.0 m mill length and a 2.4 m cut piece do not hold the same straightness in service because the piece is supported differently on site. If the profile is a mullion, a rail or a track, say how it is fixed and over what span. That sentence lets us cut and inspect against the way the part actually works, rather than against a bench number that means nothing on site. When CNC Beats the Die Some dimensions should never be pushed into the extrusion. Hole position, counterbore depth, mitre angle and any feature that has to relate to another machined face are better cut after extrusion on a CNC centre. Our rule of thumb: if the feature is a fit to another part, machine it; if it is the shape of the section itself, hold it in the die. Splitting the work that way usually gives a tighter finished part at lower total cost than an over-specified die. What We Cannot Do We do not publish a millimetre tolerance table: values depend on section, alloy and which dimensions you mark as critical. We do not hold ±0.1 mm on every dimension of a section. It applies to grooves cut for it. We do not run die casting. We do not quote against a tolerance alone; the drawing and the quantity come first. What to Send Section drawing (DXF or PDF) with the circumscribed circle Alloy and temper The dimensions that are functional, and what fits into them Surface finish and film thickness Cut length and how the part is supported in service The Numbers Behind This Page Item Value Extrusion presses 26, from 500 MT to 5,000 MT Largest section 540 mm circumscribed circle Minimum wall 0.8 mm Typical curtain wall wall 1.2 mm to 6.0 mm Mill length 6.0–7.0 m Container limit 20 ft: 5.85 m · 40 ft: 6.0 m in two cuts Minimum order 500 kg per profile New die 15–25 working days after drawing approval, plus 3–5 days sampling Anodising AA10 (10 µm) and AA15 (15 µm) Plant capacity 100,000 t/year, since 2005, Foshan These are plant facts, not tolerance values. They tell you what is available; the drawing tells us what to hold. Standards. GB/T 5237 (dimensional, high-precision class) · EN 755-1 to -9 (mechanical and dimensional) · ASTM B221 (chemical composition). Tolerance review is done against the drawing, not against a generic table.

=== Aluminum Extrusion HS Codes and Anti-Dumping: What Decides Your Duty ===
URL: https://www.linkedalu.com/knowledge/aluminum-extrusion-hs-code-and-anti-dumping-compliance.html
Published: 2026-10-09
An HS code is not customs paperwork — it selects your duty regime Aluminum extrusions enter under three headings: 7604 for bars, rods and profiles; 7608 for tubes and pipes; 7610 for structures. The heading you declare decides whether an anti-dumping order can reach your shipment at all. Most importers treat classification as data entry, delegated to a forwarder and reviewed by nobody. That assumption is expensive. Anti-dumping duty is not a marginal line item — the current United States cash deposit rate for Chinese aluminum extrusions without a company-specific rate is 86.01%, applied on top of the ordinary customs duty. One heading apart can separate a workable landed cost from an impossible one, and the difference never appears on the supplier's quotation, because it is not a supplier's number to give. Three headings cover nearly everything a buyer imports from an extrusion mill: Heading Covers Typical goods 7604 Bars, rods and profiles Solid and hollow extrusions, mill finish or anodized, cut to length 7608 Tubes and pipes Round, square and rectangular tube; seamless or welded 7610 Aluminium structures and parts of structures Fabricated frames, curtain wall units, assembled products The distinction that matters most runs between 7604 and 7610, and it turns on manufacturing stage rather than material. An extruded curtain wall mullion is 7604. The same mullion, cut, punched, assembled with pressure plates and shipped as a unitised panel, may be 7610. 7604, 7608, 7610: the line is drawn by form, not by alloy Alloy does not choose the heading. Form does. A 6063-T5 solid profile and a 6063-T5 hollow profile both sit in 7604; convert either into a round tube and the heading moves to 7608. Buyers often assume that declaring 6061-T6 or 7075-T651 changes the classification, because those alloys carry recognisable names. It does not. Heading 7604 admits every aluminium alloy; what separates it from 7608 is whether the cross-section is a shaped profile or a tube of uniform wall. That is a geometric test, not a metallurgical one. Two practical consequences follow. First, the same die can produce goods under different headings depending on what the drawing specifies. A hollow rectangular section is a profile. Draw it as a round tube and it is not. Second, further fabrication does not automatically move a profile into 7610. Drilling, punching, tapping, anodizing and machining leave the goods in 7604 — the anti-dumping scope language is explicit that fabrication alone does not remove a product from coverage. What moves goods into a structures heading is assembly into something that functions as a structure or part of one. This is where most classification errors originate: an importer assumes that because the goods arrive drilled to a project drawing, they are finished parts rather than profiles. They are not. The counterintuitive part: finishing the product can take it out of scope A raw extruded profile is inside United States anti-dumping scope. The same profile assembled into a finished window with glass installed is excluded. Duty can fall as the product becomes more finished. This runs against intuition, because more processing usually means more value and more duty. Here it can mean less. The scope language draws its line at assembly, not at value added: Your product Likely United States ADD/CVD status Raw or cut-to-length extruded bars, rods, hollow or solid profiles, tubes and pipes Inside scope Extrusions anodized, painted, machined, drilled or punched, but not assembled Inside scope A finished-goods kit — every part needed to assemble one final product, packaged together, entered unassembled, requiring no further cutting or fabrication Excluded, subject to the exact kit test Fully and permanently assembled finished merchandise — a window with glass, a door with glass, a solar panel Excluded 2xxx, 5xxx or 7xxx series above the order's copper, magnesium or zinc thresholds Excluded if the alloy tests are met Two warnings sit on that table. Adding fasteners does not create the kit exclusion. Screws and bolts in the carton do not turn a bundle of profiles into a finished-goods kit. The parts must constitute everything required for one finished product, and no further fabrication may be needed. Excluded from anti-dumping scope does not mean duty-free. Finished goods can attract a different heading, a different rate, and — in the United States — Section 232 aluminium duties, which apply to aluminium articles at 50% and to most derivative products at 25% under the proclamation in force through 2027. Section 232 is origin-neutral; it is not a China measure. Buyers who discover the scope exclusion and stop reading there often trade one duty for another. The correct question is never which duty applies, but which duties apply, and to which heading. Where Chinese extrusions actually face duty — and where they do not The United States and the European Union both have anti-dumping orders in force on Chinese aluminium extrusions. Mexico has a definitive measure on profiles and bars. Brazil's in-force list shows no measure on extruded profiles, and the Gulf duties cover flat-rolled sheet, not extrusions. Market decisions frequently get made on incomplete information in both directions — buyers avoid markets that are open, and enter markets that are closed. The table below reflects publicly available measure lists checked in late 2026. Rates, scope rulings and case status change without notice, so confirm your specific classification and origin with a licensed customs broker before committing to an order. Market Status on Chinese aluminium extrusions Note United States Order in force since 2011 AD cash deposit 86.01% for exporters without a separate rate; CVD all-others 7.37%; Section 232 layered on top European Union Order in force, under expiry review Extrusions within CN 7604 / 7608 / 7610 descriptions; first sunset review initiated 27 March 2026, duties remain in force during it Mexico Definitive measure on profiles and bars USD 1.58 per kg on Chinese-origin profiles and bars Gulf Cooperation Council Measure applies to flat-rolled product, not extrusions The duties cover painted or coated aluminium plates, sheets, strips and coils 0.2–8 mm — a different product form Brazil No measure on extruded profiles on the in-force list Verify before relying on this; figures circulating for "AD on profiles" trace to a different case India No extrusion-specific order confirmed Indian measures in this area cover flat-rolled product (HS 7606) and foil — not extrusions Two traps in that table are worth naming. The Gulf case is frequently misread. Headlines about "GCC anti-dumping on Chinese aluminium" describe flat-rolled sheet and coil. An extruder shipping profiles is not covered by that measure. Buyers who read the headline and rule the Gulf out lose an open market. India is frequently misread in the opposite direction. Measures exist on flat-rolled aluminium, and are routinely repeated as if they covered extrusions. They do not. Anti-dumping duty is a deposit, not a final number Anti-dumping duty is collected as a cash deposit at the time of entry. It is recalculated in annual administrative reviews, and the final rate can be lower or higher than the deposit — producing refunds in some cases and retroactive bills in others. Importers plan around the deposit figure as though it were a price. It is closer to a provisional charge that settles later, sometimes years later, across a period that has already closed. Three consequences follow for how you buy. Budget the review risk, not just the deposit. A supplier quoting against a deposit rate is quoting an interim number. If the reviewed rate rises, the difference becomes a retroactive liability on entries already made. Company-specific rates are worth verifying. A named exporter holding a separate rate keeps that rate unless it appears in a review's appendix. An exporter without one falls to the country-wide rate — a gap wide enough to change which supplier wins an order. Ask any supplier claiming a low rate to identify it precisely. Keep the records a review will demand. When a rate is challenged, the burden falls on documentation of where metal was cast, extruded and finished. Records assembled after the fact rarely satisfy the test. What a mill test certificate proves — and what it does not A mill test certificate reports chemical composition and mechanical properties per heat, against a stated standard. It does not establish the HS heading, the country of origin, or whether your product sits inside an anti-dumping scope. Buyers frequently treat the MTC as a general-purpose compliance document. It is narrower than that. What it legitimately supports: Alloy and temper conformance to GB/T 5237, EN 755 or ASTM B221 Chemical composition limits per heat Tensile strength, yield strength and elongation Hardness where specified Coating or anodic film thickness where the finish is within the report's scope What it does not do: it will not tell you whether your 80×40 hollow section is 7604 or 7610, and it will not tell you whether the goods fall within an order's scope. Those are classification and scope questions, answered by tariff schedules and scope rulings — not by a materials report. Where a buyer genuinely needs certainty on origin, the instruments are different: production records, casting documentation and, in some jurisdictions, origin declarations or rulings. An MTC alone does not carry that weight. Six classification errors that produce retroactive duty bills Most retroactive anti-dumping assessments trace to a small set of repeatable mistakes: classifying by alloy instead of form, ignoring assembly stage, and treating fabricated profiles as finished goods. The recurring errors, in the order they tend to appear: 1. Classifying by alloy. Declaring 6061-T6 as though the alloy were the heading. Alloy selection is a 7604 question, not a heading question. 2. Ignoring the assembly-stage test. Entering an assembled unit under the profile heading, or a profile under a structures heading, because the physical goods looked similar on the loading dock. 3. Assuming fabrication removes scope coverage. Anodizing, punching and machining do not remove a profile from anti-dumping scope. They also do not move it to 7610. 4. Treating a bundle as a kit, or a kit as assembled goods. The kit exclusion has a specific test: everything needed for one finished product, packaged together, no further fabrication required. Cartons with fasteners added do not meet it. 5. Reading the headline instead of the scope. "AD on aluminium from China" in a news item may describe foil, sheet, or one product form. Scope is defined by product description, not by the word aluminium. 6. Assuming the duty ends when the order expires. Orders come under expiry reviews, and duties commonly remain in force through the review. Treating a pending expiry as today's duty-free window is a planning error. How to verify a classification before you commit to an order Get the classification rationale in writing, check it against the importing country's tariff schedule, and where the goods sit near a scope boundary, obtain a written broker opinion or a formal scope ruling. A workable sequence, in order: 1. Ask the supplier for a written classification rationale — heading, form test, and the manufacturing stage assumed. A supplier who cannot state why a heading applies is guessing. 2. Check the rationale against the destination tariff schedule. The same goods can classify differently across jurisdictions and the tests are not identical — the United States applies alloy-series thresholds, while the EU applies an aluminium-content test, and welded tube sits outside the EU order while the US order covers extruded tube. 3. Identify whether the product sits near a scope boundary. Kits, welded end-caps, a bracket the assembler must drill — these are the cases where a summary is not enough. 4. Where the boundary matters, get a formal answer. In the United States this is a scope ruling request through the Commerce Department's ACCESS system; elsewhere it is a written opinion from a licensed broker or trade counsel. Self-classifying from a summary article is how importers overpay for years or receive a retroactive bill. 5. Re-check before each new order. Scope rulings are issued continuously. A classification that was correct at the last shipment is not evidence about this one. Classification, scope and duty rate are three separate questions with three separate answers, and only the first two are questions a mill can help you answer. Duty rate and origin treatment belong to your customs broker. What a mill can legitimately do is state what it produced, to which standard, and at what manufacturing stage. That is what a mill test certificate and a dimension report are for, and it is the input your broker needs. If you are working through a classification question on an extrusion order, our engineers will state the alloy, temper, standard and fabrication stage of any profile we quote, in writing. We supply FOB Shenzhen or Guangzhou, CIF on request, with mill test reports per heat and coating thickness records per lot. Send the drawing and the destination market, and the quotation will carry the specification data your customs entry depends on.

=== Aluminum Profile Surface Finishes: Anodizing, Powder Coating, PVDF ===
URL: https://www.linkedalu.com/knowledge/aluminum-profile-surface-finishes-anodizing-powder-coating-pvdf.html
Published: 2026-09-17
Two extrusion lines can turn out profiles with identical alloy, identical tolerances and identical mechanical properties, and the finished parts can still fail differently on the same building. The difference is almost always the surface finish — and the fact that the finish was chosen from a colour chart instead of from a standard. This page sets out the finish families we run, the standard that defines each one, the coating thickness that standard implies, and where each one is the wrong answer. Mill finish: the baseline, not a finish A mill finish profile is the extrusion as it leaves the press and cools — no anodizing, no coating. It carries the visible extrusion lines and handling marks of the process, and its oxide layer is the thin natural one (a few nanometres, growing slowly in air). Mill finish is correct for profiles that will be fabricated and then coated or painted by the customer, for parts welded into assemblies and finished afterwards, and for fully concealed structural members. It is the wrong answer anywhere the profile is visible and exposed: without a coating there is nothing to stop the surface from staining, and the natural oxide offers no meaningful protection in a chloride environment. Commercial tolerances for mill finish extruded profiles are defined by EN 755-9 (profiles) and EN 12020-2 (precision profiles in EN AW-6060/6063). Anodizing: hard, integral, repairable only by re-anodizing Anodizing is an electrochemical conversion of the aluminium surface itself into aluminium oxide. Because the oxide grows out of the metal rather than sitting on top of it, it cannot flake, chip or peel away from a substrate the way a coating can. It is electrically non-conductive, it does not hide the extrusion lines or the metal's grain, and it is the only finish on this page that keeps a distinctly metallic appearance. Architectural anodizing is specified by coating thickness, using the familiar AA designations: AA15 nominally 15 µm and AA20 nominally 20 µm, for interior and exterior exposure respectively. Those designations and the performance requirements around them come from the AAMA 611 specification for anodized architectural aluminium. Process control and the anodizing layer itself are described in EN ISO 12373, and the sealing quality of the anodized layer — thickness, sealing ratio, colour and abrasion resistance — is what the acid-dissolution test in ISO 3210 is used to verify. The trade-offs are real. Anodizing is a single-colour process: the colour comes from the alloy, from the anodizing conditions, or from electrolytic colouring, so there is no matching an arbitrary RAL number. On 6xxx extrusions it also shows the metallurgical difference between lots, and darker colours show it more. Deep-drawn or heavily formed parts can crack their anodized layer at tight radii. Powder coating: the most colour-flexible option Powder coating is a dry polymer powder sprayed electrostatically and cured into a continuous film, typically 60–80 µm for architectural work. It can match essentially any RAL, it covers the extrusion surface uniformly including edges, and it tolerates handling and installation damage better than a thinner coating. For architectural aluminium the defining standard is EN 12206-1 (organic coatings on aluminium for architectural applications), which covers film thickness, adhesion, and the accelerated weathering a coated profile has to survive. The industry quality schemes Qualicoat (coatings) and Qualanod (anodizing) sit on top of those standards and are what specifiers usually ask for by name when they want the coating supply chain audited rather than just the finished part tested. The failure modes are the ones you would expect of a polymer film: chalking and colour change at the surface, and — if the pretreatment was incomplete — filiform corrosion creeping from a scratch or a cut edge. Pretreatment chemistry, not the powder, is where most premature coating failures actually originate. PVDF: specified for the exposure, priced for the project PVDF (polyvinylidene fluoride) coatings are fluoropolymer systems applied as a two-coat or three-coat build, typically 25–40 µm, over a primer. Their colour and gloss retention under UV is the reason they exist: AAMA 2605, the most demanding of the AAMA coating specifications, is built around 10-year South Florida exposure testing, against 5 years for AAMA 2604 and one year for AAMA 2603. That is the honest basis for the choice: AAMA 2605 is the specification to write when the facade has to still match the original colour a decade from now in a high-UV or coastal environment, and it is normally the most expensive of the liquid-applied options. Specifying PVDF for an interior partition is paying for weathering that will never be tested. Electrophoresis (E-coat) and the smooth anodized look Electrophoretic coating deposits an organic film from a water-based bath under an applied voltage. It is frequently applied over an anodized layer, which is the combination usually meant by "electrophoresis finish": the anodizing gives hardness and colour, and the E-coat closes the surface, removes the sticky feel traditional sealing can leave, and raises corrosion resistance. The result is a very smooth, even, high-gloss surface that holds up better than plain anodizing in polluted or lightly coastal air, at the cost of another process step and another bath to control. Wood grain and bronze: finishes that imitate other materials Wood grain is a sublimation transfer onto a powder-coated profile: the cured coating is heated with a printed film so the pattern diffuses into it. It exists to satisfy planning authorities and customers who want the look of timber without its maintenance, and it belongs on window and door systems and on facade detail where the pattern carries across a visible joint. Bronze anodized covers the brown-to-black range produced by electrolytic colouring (tin or nickel salt baths deposit metal into the pores of the anodized layer before sealing) or by dyeing. It is the traditional colour of architectural aluminium, it hides handling marks better than clear anodizing, and — like all anodizing — it is fabrication-tolerant because the layer is part of the metal. Mechanical finishes: polishing and sand blasting Polishing is mechanical and/or chemical brightening, used for trim, reflectors and profiles that have to read as polished metal. It is normally followed by a protective anodized or E-coat layer, because a bare polished surface scratches and oxidizes quickly. Sand blasting is the opposite intent: a controlled abrasive treatment that produces a uniform matte texture, usually as the pretreatment for anodizing when a diffused, non-reflective surface is wanted and the extrusion lines have to disappear. Thermal break is not a finish Worth separating explicitly, because it often appears in the same material list: a thermal break is a construction, not a coating. The profile is extruded in two parts and rejoined by a polyamide strip (typically PA66 with 25% glass fibre) that interrupts the path for heat and sound. Those assemblies are tested as systems, for mechanical strength and for thermal performance, rather than as finishes — see the window and door profiles and curtain wall profiles where we run them. Choosing: match the finish to the exposure, then to the budget Interior, not visible, or to be coated later — mill finish. Interior, visible, metallic look — AA15 clear anodizing; powder coating if the colour has to match a specification. Exterior inland, normal urban air — AA20 anodizing, or powder coating to EN 12206-1. Both are defensible; pick on appearance and on how repair will be handled on site. Exterior, coastal or high-UV, colour must survive — PVDF to AAMA 2605. This is the case the specification exists for. Anodized look with better surface smoothness and corrosion resistance — anodizing plus electrophoresis. Timber appearance, low maintenance — wood-grain sublimation over powder coating. The two questions that decide most projects First: will the part be fabricated after finishing? Cutting, drilling, welding and bending all break a surface film. Anodizing survives fabrication as a converted surface; a coating leaves bare metal at every cut and needs touching up. Second: what will the surface look like in ten years, and who is accountable if it does not? That question turns AAMA 2603 / 2604 / 2605 from a line item into the specification, and it is worth writing into the purchase order rather than leaving to the powder supplier. Send us the drawing and the exposure the profile will see, and we will quote the finish against the standard rather than against a colour name — including which of these options we would not use on your building.

=== Extruded vs. Die-Cast Motor Housings: An Engineer's Guide to Choosing ===
URL: https://www.linkedalu.com/knowledge/extruded-vs-die-cast-motor-housings-an-engineers-guide-to-choosing-linkedalu.html
Published: 2026-08-12
Two Processes, Two Sets of Trade-offs When you specify an aluminum motor housing, the first fork in the road is not alloy or surface finish. It is the manufacturing process. Extrusion and die casting both produce aluminum shells, and that is roughly where the similarity ends. They differ in what shapes are possible, what the material can do thermally and structurally, what you pay up front and how fast you can iterate. Extrusion pushes a heated aluminum billet through a shaped die opening under high pressure. The profile emerges as a continuous length with a constant cross-section, and you cut it to housing length and machine the bore, spigots, end faces and mounting holes afterwards. Die casting injects molten aluminum into a reusable steel mold under high pressure, filling the entire cavity in seconds to produce a near-net-shape part with complex external geometry. The key phrase is constant cross-section: extrusion gives you that, and die casting does not need it. Thermal Performance: The Extrusion Advantage Heat kills motors, and a housing that shaves a few degrees off the winding temperature can add years of insulation life. Material density matters Extruded aluminum is wrought material, hot-worked from a cast billet, which refines the grain structure and closes internal voids. Die-cast aluminum solidifies from liquid in seconds, so even with vacuum assist it carries microscopic gas porosity distributed through the wall. Those voids insulate. In practice an extruded 6063 housing conducts heat roughly 10-20 percent more effectively through the wall than the same wall thickness in die-cast A380. Fin geometry flexibility With extrusion, fin height, thickness, pitch and taper are built into the die. You can pack high-aspect-ratio fins around the perimeter, exactly the geometry a die-cast mold struggles with because the metal freezes before it reaches the fin tip. For high-density natural-convection cooling, extrusion is the standard for a reason. Die casting can include fins, but they are shorter, thicker and carry generous draft angles, and if they fill at all, tip porosity reduces their real heat transfer below the modeled value. Structural Integrity: Porosity, Pressure Tightness and Fatigue Die-cast parts always contain some gas porosity. For a motor housing this matters when the housing forms part of a sealed enclosure and becomes a leak path, when mounting feet are welded on and expanding gas causes blowout, and under vibration or thermal cycling, where porosity acts as a stress raiser. High-pressure die casting reduces porosity without eliminating it, and vacuum die casting gets close at a cost. Extruded profiles are inherently pore-free. Weldability is excellent, so a 6061-T6 extrusion welds cleanly, while welding a die-cast A380 housing is a gamble. For EV traction motors or any design where the housing is a structural member, this factor alone can decide the process. Strength and ductility differ in character as well as magnitude. Die-cast A380 has respectable tensile strength around 324 MPa but very low elongation, typically under 4 percent. Extruded 6061-T6 delivers roughly 290 MPa tensile with 8-10 percent elongation, so it bends before it breaks. In a motor that sees shock loads, vibration or thermal expansion stress, that ductility margin matters. Design Freedom: Where Die Casting Wins Complex external geometry - mounting flanges with thick bosses on two sides, an integrated connector box and asymmetric stiffening ribs, all formed in one shot. Extrusion cannot produce side features, so they must be machined from solid or bolted on. Undercuts and partial features - extrusion dies can create internal splines, screw bosses and ribbed bores as long as they run the full length of the profile. Die casting can form partial-depth pockets, side holes and recesses that do not pass through the whole part. Wall thickness variability - die casting handles a 2 mm wall next to a 10 mm boss far more gracefully than extrusion, though solidification shrinkage must be managed. The extrusion workaround - extrude a blank with a thicker wall section and machine away material to create pockets, grooves and mounting features. It adds a step, but keeps the thermal and structural benefits while adding geometric complexity. Tooling Cost, Lead Time and Iteration Speed Factor Extrusion Die casting Tooling cost Lower, single-figure thousands Higher, often an order of magnitude more Lead time to first samples A few weeks Two to three times longer Order quantity to start A few hundred kilograms Several hundred to a thousand pieces Design change Modify the die at modest cost Mold modification is limited and expensive Iteration risk Low: tweak the profile and re-run High: a wrong mold costs the full tooling budget again If you expect two or three housing revisions during prototyping, extrusion saves weeks and money at every turn: the die is a simple steel disc with a shaped aperture. Die casting pays back once the design is frozen and volumes are high enough for lower per-part machining to offset the mold investment. Dimensional Precision and Post-Processing Both processes need secondary machining, but the starting blank is different. An extrusion gives you a very consistent blank: wall thickness, straightness and cross-section are tightly controlled because the die opening barely changes over a run, and there is no rapid-solidification stress locked into the material. Bore roundness of 0.05 mm or better is straightforward with proper machining, and finer roundness is achievable with honing. Die casting starts closer to net shape, so you machine less, but the process adds variability: parting-line flash, draft angles and distortion during cooling. Machining setups must compensate, which slows cycle times, and critical bearing bores carry extra stock to clean up surface porosity. Surface finishing follows from the same difference. Extruded surfaces are dense and take anodizing beautifully, so black anodized extruded servo housings are an industry standard. Anodizing a die casting is difficult because silicon in the skin and subsurface porosity cause discoloration and poor adhesion, so most die-cast motor housings are painted, powder coated or left as-cast. If the housing must be anodized, extrusion is almost always the answer. How to Decide Choose extrusion when the housing is tubular or prismatic with a constant cross-section, when heat dissipation needs tall or dense fins, when an anodized finish is required, when the housing may be welded or must be pressure tight, or when you are prototyping and expect design changes. Choose die casting when the housing has complex external geometry that would be expensive to machine, when annual volumes are high and the design is frozen, when features must change along the housing length, or when a painted finish is acceptable. Consider the hybrid: an extruded body tube for thermal and structural performance, with die-cast or CNC end bells and mounting feet bolted or friction-stir welded on. It is not always the cheapest option, but for high-power-density servo motors it is often the best-performing one. The Bottom Line For the tubular, finned housings that dominate the servo and stepper motor world, extrusion is the default: thermally superior, dimensionally stable and dramatically cheaper to prototype. Die casting earns its place when the shape becomes too complex for a constant cross-section and volumes justify the tooling. Send us the cross-section or 3D model for a DFM review and extrusion tooling and per-part costs.

=== 7075, 7050, and 7005: When 6061 Isn't Strong Enough ===
URL: https://www.linkedalu.com/knowledge/7075-7050-and-7005-when-6061-isnt-strong-enough.html
Published: 2026-07-29
When 6xxx Runs Out of Strength Most aluminum profiles leave an extrusion plant in 6063 or 6061. They extrude cleanly, anodize evenly and cost what customers expect to pay. Then a drawing arrives with a different note on it: 7075-T6. That is the point where the project changes character, because the 7xxx family is the highest-strength group of aluminum extrusion alloys in commercial use. In the T6 temper, 7075 reaches a tensile strength around 572 MPa, nearly double 6061-T6 and close to mild structural steel. That opens demanding applications where aluminum normally cannot compete. It also brings a hard set of manufacturing problems that make 6xxx extrusion look easy. This guide covers the three 7xxx alloys encountered most often: 7075, 7050 and 7005. The Three Alloys at a Glance Alloy and temper Tensile Yield Weldability Primary advantage Typical use 7075-T6 approx. 572 MPa approx. 503 MPa Not fusion weldable Highest available strength Aircraft fittings, high-load structural parts, sports equipment 7050-T74 approx. 524 MPa approx. 469 MPa Not fusion weldable Stress corrosion resistance and thick-section uniformity Aerospace frames, thick structural sections 7005-T6 approx. 350 MPa approx. 290 MPa Readily weldable High strength plus fusion weldability Welded bicycle frames, motorcycle forks, sports equipment 6061-T6 (reference) approx. 290 MPa approx. 240 MPa Weldable Baseline structural alloy General framing, automotive, machinery 7075: The Strength Benchmark 7075 combines zinc (5.1-6.1 percent), magnesium (2.1-2.9 percent) and copper (1.2-2.0 percent), forming fine MgZn2 precipitates that give the matrix its extraordinary performance. It is the alloy engineers reach for first when strength dominates every other consideration. The trade-offs are severe. 7075 resists extrusion strongly, wears dies aggressively, and carries high scrap risk on complex sections. Anodizing produces a dull yellowish-gray finish rather than the bright metallic appearance of 6063, so it is a poor choice for visible decorative work. It also has poor resistance to stress corrosion cracking in the T6 temper when loaded continuously in a corrosive environment, which is exactly the problem 7050 was created to solve. 7050: The Aerospace Upgrade 7050 lowers overall copper content and replaces chromium with zirconium (0.08-0.15 percent) as the grain-refining dispersoid. The result is a family of tempers that keeps most of 7075's yield strength while dramatically improving resistance to stress corrosion cracking when supplied in the overaged T74 condition. Stress corrosion resistance - in the overaged temper, 7050 far exceeds 7075-T6, which is why it dominates thick aerospace structural sections. Low quench sensitivity - 7050 holds more uniform properties across thick walls, where 7075 shows a noticeable drop from surface to core. Damage tolerance - improved fracture toughness and fatigue behavior at equivalent strength. Cost and availability - narrow mill supply, tighter process windows and higher unit cost than any 6xxx alloy. 7005: The Weldable Member of the Family 7005 is the practical exception in the 7xxx group: it can be fusion welded without the catastrophic loss of properties that makes 7075 and 7050 unsuitable for welded structure. Its zinc and magnesium levels are lower and it uses zirconium for grain control, giving roughly 350 MPa tensile in T6 with about 290 MPa yield. That combination is why welded bicycle frames, motorcycle components and high-performance sports equipment are frequently built from 7005. You get a strength level that comfortably beats 6061-T6 while retaining the ability to weld the assembly, at a cost premium that is meaningful but manageable. Why Extruding 7xxx Alloys Is Difficult Massive flow stress At extrusion temperatures of about 380-420°C, 7xxx alloys exhibit far higher flow stress than 6xxx. A press that pushes a 6063 billet comfortably may sit at its absolute tonnage limit on the identical profile in 7075. Order-of-magnitude slower production Where 6063 runs at 30-50 m/min on a given geometry, 7075 on the same tool often runs at only about 2-5 m/min. Throughput collapses, and so does the cost per kilogram argument in favor of aluminum. Extreme tooling wear 7075 contains hard intermetallic compounds such as Al2CuMg and MgZn2 that behave as micro-abrasives under heat and pressure. A die that produces 60-80 tons of 6063 profile may fall out of tolerance after only 15-25 tons of 7075. Narrow thermal window at the exit Exit temperature control is critical. Run too hot and the profile tears or cracks; run too cold and the press stalls or the surface tears at the die land. Quench must then be fast enough to develop properties without inducing distortion in thin walls. Finishing and Corrosion Realities Anodizing 7xxx alloys does not produce the clean, bright film customers expect from 6063. The copper content drives a dull, darker appearance and, at the high end of the range, the oxide quality is harder to control. Anodized architectural film thicknesses of 10-25 µm are normal practice on 6xxx profiles; applying the same specification to 7075 is technically possible but rarely satisfies an appearance requirement. Powder coating at 40-120 µm covers the surface reliably and is the more common route for 7xxx parts that must look good, while conversion coating and primer systems are standard for aerospace parts that will be painted. Buyer's Engineering Checklist Confirm that the strength requirement genuinely excludes 6061-T6. Many 7075 enquiries dissolve once the real load case is calculated. Prepare for long lead times: 7xxx billets are narrower in supply than 6063 or 6061. Optimize wall thickness for extrudability. Walls that fill effortlessly in 6063 can fail to fill or tear in 7075. Ask about die material and maintenance policy, because tool life is measured in tens of tons, not hundreds. Decide the finish before you finalize the alloy, not after. Confirm the temper explicitly. T6, T651, T73 and T74 are not interchangeable, and heat treat condition drives both strength and corrosion performance. The Bottom Line 7xxx alloy extrusions occupy a real and necessary place in structural engineering. When a design needs an aluminum profile that competes with structural steel on yield strength while cutting component weight substantially, and when weight saving justifies the cost and the slow extrusion, 7xxx is the definitive answer. Where it is not needed, 6061-T6 or 6005A-T6 will do the job for a fraction of the trouble.

=== How Extrusion Dies Shape Aluminum Profile Quality: Steel, Tolerances, and Surface Defects Explained ===
URL: https://www.linkedalu.com/knowledge/how-extrusion-dies-shape-aluminum-profile-quality-steel-tolerances-and-surface-defects-explained.html
Published: 2026-07-08
Profile Quality Is a Die Story, Not an Alloy Story Two extrusion plants can run the same 6063-T5 billet chemistry on presses of similar tonnage and ship profiles that are not remotely comparable. One arrives with wall thickness inside 0.08 mm, a uniform matte anodized surface and no visible die lines. The other shows 0.25 mm of wall drift across the run, faint longitudinal lines that only appear after anodizing, and short blisters near the ends. Buyers blame the alloy. The alloy is rarely the cause. A die operates in a brutal environment: aluminum heated to roughly 500°C is forced through a steel tool under thousands of tons of pressure at exit speeds that can exceed 50 m/min. The die surface cycles between peak extrusion temperature and the cooler gap between billets, so every billet is a thermal shock and every meter of profile is an abrasion test. The tool's design, its steel, its heat treatment and its maintenance record are what you are actually buying. Die Steel: Hot Hardness Beats Catalog Hardness Most aluminum extrusion dies are cut from hot-work tool steel of the AISI H13 family (4Cr5MoSiV1 in Chinese designations), typically supplied around 48-52 HRC before nitriding. What matters at 500°C is not room-temperature hardness but hot hardness and temper resistance. A steel that softens early loses bearing geometry, and once the bearing geometry moves, wall thickness moves with it. Cr-Mo-V balance - chromium provides hardenability, while molybdenum and vanadium carry temper resistance at working temperature. Steel cleanliness - segregation and inclusions in the die block become crack initiation sites under repeated thermal cycling. Heat treatment discipline - vacuum hardening with controlled tempering; a block that retains austenite will creep under load. Die design - bearing balance, port or porthole geometry, and welding chamber volume decide whether the profile fills evenly. Nitriding: The 0.1-0.25 mm That Decides Surface Quality Gas or plasma nitriding creates a hard case, commonly 0.10-0.25 mm deep at roughly 900-1100 HV on the working surfaces. That layer resists the abrasive flow of aluminum across the bearing, and it is also what stops pick-up (aluminum welding itself to the die) from starting. A shallow, brittle or uneven case chips away, and a chipped bearing prints a permanent die line into every meter of profile until the die is pulled from the press. Nitriding is not a one-time treatment. On standard 6063-T5 architectural work, a reasonable maintenance interval is a pull-and-inspect every 50 to 80 tons, with polishing and re-nitriding as bearing condition requires. Ask to see that log before you place the order, not after the first complaint. Bearing Length and Flow Balance Metal flows fastest where the bearing, the land length behind the die orifice, is shortest. Die designers extend the bearing where material must slow down and shorten it where flow starves. Get that balance wrong and the profile leaves the die with hot-cracking webs on one side and a lumpy, overfilled flange on the other. Buyers often describe this as an alloy problem; it is a tooling problem. Why Wall Thickness Drifts During a Run 1. Thermal growth of tool and press The die, container and stem expand as they soak up heat from the first billets. Unless the press is held at a stable thermal state, profiles run at the start of a shift can measure differently from profiles run four hours later. 2. Bearing wear and pick-up Aluminum deposits on the bearing effectively reduce the orifice. Flow on that side drops and material is pushed into adjacent walls. The symptom is a slow, monotonic drift rather than random scatter. 3. Alloy aggressiveness 6063 is comparatively forgiving. 6061, with its higher magnesium and silicon content, wears bearings noticeably faster and needs more frequent pull-and-polish cycles for the same tonnage. One die will hold tolerance for far fewer tons of 6061 than of 6063. 4. Billet quality and temperature uniformity Billets with heavy surface oxide, taper or uneven preheat feed the die unevenly. Taper heating and scalping are not luxuries on thin-wall work. Surface Defects and What Each One Tells You Defect Usual root cause Corrective action Longitudinal die lines Damaged, chipped or poorly polished bearing surfaces Pull the die, polish the bearing, re-nitride before restarting Streaks or color banding after anodizing Iron or copper segregation, billet surface contamination, inconsistent quench Tighten billet limits, improve sawing and handling, verify quench rate Pick-up (metal dragging) Bearing length mismatched to speed, thin nitride case, poor lubrication Rebalance the bearing, adjust extrusion speed, re-nitride Tear marks and speed cracks Exit speed beyond the alloy's hot ductility at that temperature Reduce ram speed and billet temperature, or redesign the bearing Chatter marks Press vibration, poor run-out support, unstable puller Inspect puller, support and container alignment Blistering Trapped air or contamination at the billet surface Scalp billets, control heating atmosphere, check die venting Writing Tolerances on the Drawing Extruded profile tolerances come from tables, not from a single plus-or-minus number. GB/T 5237.1, EN 755-9 and ASTM B221 all define classes by dimension type, wall thickness band and profile size. A well-built die on a stable press can hold around ±0.10 mm on critical architectural dimensions, but that is a demonstrated capability, not an entitlement. The drawing should name the standard and the class, and the supplier should confirm capability against it before quoting. Where a dimension is cosmetic rather than functional, say so: it frees the plant to run faster and quote lower. A Procurement Checklist That Actually Filters Suppliers "What is your pull-and-inspect interval for 6063-T5 architectural dies, expressed in tons?" A serious answer lands in the 50-80 ton range for standard work. "Can we review the die maintenance and re-nitriding log for an active profile?" Plants that maintain dies keep records. "What die steel grade and hardness do you specify, and is a steel certificate available?" "What is your measured wall thickness capability, and over how many samples?" "Who supplies your billets, and what iron limit applies to architectural alloy?" "Do you polish or re-nitride on a schedule, or only when a defect appears?" The Bottom Line A premium die can cost 30 to 50 percent more up front. Over the life of a product run it usually earns that back several times: fewer rejected profiles, less press downtime for emergency tool changes, tighter and more repeatable wall thickness, and a surface that comes off the press already close to cosmetic. When an extrusion quote looks unusually cheap, the tooling budget is usually where the difference was taken out.

=== 6005 vs 6005A vs 6061 vs 6063: What's the Real Difference? ===
URL: https://www.linkedalu.com/knowledge/6005-vs-6005a-vs-6061-vs-6063-whats-the-real-difference.html
Published: 2026-06-14
The Gap Between 6063 and 6061 If you have spent any time in aluminum specifications for a solar mounting system, a structural railing or a vehicle frame, you have hit the same wall. 6063 feels too soft for the load case, 6061 feels like overkill and costs too much per meter, and then someone mentions 6005 or 6005A. Here is what the difference actually is, and where each alloy earns its place. What 6005 and 6005A Actually Are 6005 is a magnesium-silicon alloy positioned deliberately between 6063 and 6061. It carries more silicon and magnesium than 6063, so it age-hardens to a much higher strength, while retaining far better extrusion behavior than 6061. 6005A is the refined version: a tighter chemistry window with a controlled manganese-plus-chromium dispersoid addition that improves quench sensitivity and grain structure, and a tighter limit on copper. That copper limit matters more than it looks. Copper raises strength but reduces corrosion resistance and can cause discoloration and blotching during anodizing. By capping copper lower, 6005A delivers more consistent anodized appearance and slightly better corrosion performance than a higher-copper variant of the same family. Mechanical Comparison Alloy and temper Tensile (min) Yield (min) Elongation Character 6063-T5 160 MPa 110 MPa 8% Best extrudability and surface, lowest strength 6005-T5 260 MPa 215 MPa 9% The middle ground, good surface, much stronger than 6063 6005A-T5 270 MPa 225 MPa 8% Refined chemistry version of 6005-T5 6005A-T6 285 MPa 240 MPa 8% Further heat treatment, approaching 6061 strength 6061-T6 290 MPa 240 MPa 8% The structural standard: weldable, slower to extrude The progression is the whole story. 6005A-T6 lands within a few percentage points of 6061-T6 on yield strength, yet it extrudes faster, costs less per meter, and holds a higher proportion of its strength in the as-welded condition. If a design is even marginally inside the strength envelope of 6005A-T6, switching down from 6061-T6 often saves real money. Why Not Simply Use 6061 Everywhere? Because you pay for that strength three times over. It extrudes slower, so the press produces fewer meters per hour. It produces a worse surface on complex shapes, which matters if the profile will be anodized and visible. And it wears dies faster, which shows up as more frequent tool maintenance and shorter tool life. A 6061 rail may be stronger on paper, but on a section with fine teeth the die wears quickly and the anodized channel finish can vary. 6005A is where the balance sits. Extrusion Speed and Real Cost per Meter 6063 extrudes fastest: up to roughly 50-60 m/min on simple architectural sections. 6005A runs at roughly 80-90 percent of the 6063 speed on the same geometry. 6061 runs at roughly 60-70 percent of the 6063 speed, and less on thin-walled hollows. Die wear follows the same order: 6061 consumes tool life fastest, and 6063 is gentlest. On a long production run those percentages are not academic. They translate directly into cost per kilogram quoted back to you. The Temper Question: T5 or T6 in the Same Alloy If your 6005A-T5 design is close to a deflection or stress limit, stepping to T6 within the same alloy is usually easier than redesigning the section or moving to 6061. The chemistry does not change and the die does not change; only the heat treatment cycle after extrusion changes. That makes the T6 upgrade a low-risk lever when a calculation comes back marginal. Welding: Where 6005A Earns Its Place In T5 or T6 temper, 6005A retains a higher proportion of its strength in the as-welded condition than 6061-T6 does. That single property is why it is a preferred alloy for welded aluminum structures such as trailer frames, truck bodies and some solar support frames, where the heat-affected zone of a 6061-T6 weld would force an expensive post-weld heat treatment or an upsized section. Where Each Alloy Makes Sense 6005 and 6005A-T5: solar, railings and medium structures You get 260-270 MPa tensile in a profile that still extrudes well and takes anodizing or powder coating without trouble. Solar rail profiles often mix small screw channels with a load-bearing body, which is exactly the geometry that punishes 6061 tooling. 6005A-T6: when you are right at the T5 limit Use it when the calculation is close but the section is already optimized. Recover the margin in the heat treatment cycle rather than in a new die. 6061-T6: heavy structural and highly machined parts When loads are genuinely high, when the part is mostly machined, or when the section is simple enough that slow extrusion does not hurt much, 6061-T6 remains the industry standard and the easiest alloy to buy. 6063-T5: lowest cost per meter and the best surface Nothing beats it for architectural frames and visible trim where loads are low and appearance is everything. Quick Decision Table Your priority Best choice Reason Lowest cost per meter, best surface, light loads 6063-T5 Fastest extrusion, best anodizing response Best balance of strength, cost and finish 6005A-T5 Roughly 70 percent more tensile than 6063-T5 with good extrusion behavior Maximum strength without 6061 tooling penalties 6005A-T6 Approaches 6061-T6 strength, extrudes faster Maximum strength, weldable, structural 6061-T6 Long-established structural standard The Detail Nobody Mentions: Availability 6063 and 6061 are universally stocked. 6005A is common but not universal: some plants only run it to order, and standard die libraries for it are smaller. If your project depends on a specific mill finish or a standard profile in 6005A, confirm availability before you freeze the design, or budget for a new die. The Bottom Line 6005A is not a compromise between 6063 and 6061 so much as a deliberate optimization: nearly 6061 strength with much of 6063's extrudability and finish quality. For solar mounting, structural railings, welded frames and anything with fine visible detail under load, it is usually the cheapest way to hit the numbers.

=== Aluminum Sunroom, Screenroom & Veranda Problems and Solutions: Structural, Thermal, Leaks, Finishing ===
URL: https://www.linkedalu.com/knowledge/aluminum-sunroom-screenroom-veranda-problems-and-solutions-structural-thermal-leaks-finishing.html
Published: 2026-06-03
The Five Most Common Sunroom Problems, Fixed at the Design Stage Sagging beams, water on the floor, fogged frames and cracked glass are not maintenance mysteries. In almost every case the root cause can be traced back to a decision made before the first extrusion die was cut: an alloy choice, a wall thickness, a thermal break, a drainage path or a finish specification. This guide walks through the five problems that account for most sunroom, screenroom and veranda failures, and what to change at the drawing stage to prevent them. Problem 1: Beams and Rafters That Deflect Under Load The visible symptom is a roof line that sags or a door that stops closing square. The cause is that the profile's section modulus is too low for the span and the load. Many kit sunrooms use the same 6063-T5 thin-wall sections intended for window frames. That is perfectly adequate for a two-meter vertical mullion, and inadequate for a four-meter roof rafter carrying snow. Alloy and temper levers Spans under about 2.5 m with light loads: 6063-T5 is usually adequate if the section is deep enough. Spans over about 2.5 m, or any roof with a real snow load: move to 6063-T6 for roughly 30 percent more yield strength in the same profile. Spans over about 4 m: use 6061-T6, which nearly doubles the yield strength of 6063-T5 and welds acceptably, or step to 6005A-T6. Check deflection to a stated limit, such as L/180 for roof members, rather than checking stress alone. Glazed roofs fail visually long before they fail structurally. The other lever is geometry: it is frequently cheaper to deepen the rafter section than to move up an alloy family, because a deeper profile raises section modulus far faster than an alloy change raises strength. Problem 2: Thermal Bridging and Condensation Fogged glass, dripping frames and cold interior surfaces inside a sunroom almost always trace to a continuous metal path through the frame. Aluminum conducts heat roughly a thousand times better than the polyamide materials used for thermal breaks, so an unbroken profile carries interior warmth straight out to the cold exterior skin. Specify polyamide thermal break profiles (typically PA66 with glass fiber reinforcement) for any conditioned sunroom. Insist that the thermal break is mechanically locked properly: knurled or otherwise deburred aluminum surfaces that grip the polyamide, not a push-fit strip. Check that the break is continuous and not interrupted by fixing screws through the thermal barrier. For glazing, specify warm-edge spacers and a sealed unit with a proper desiccant, since fogging between panes is a seal failure rather than a frame problem. Problem 3: Water Where It Should Not Be Leaks at the sill, staining on the ceiling and water standing in the bottom rail are drainage failures. Water always gets in at some point; the design question is where it goes next. Integrate drainage into the extrusion itself: sloped internal channels, weepholes and baffled outlets that discharge to the exterior face. Provide pressure equalization so that wind-driven water is not pushed inward by a pressure differential. Detail sill pans and thresholds so that any water reaching them drains out, not into the floor build-up. Specify the correct gasket system: EPDM or silicone with welded corners rather than mitered and glued corner joints in exposed positions. For sloped glazing, use continuous baffled weathering and never rely on sealant as the primary water barrier. Problem 4: Finish Failures in Real Environments Chalking, color shift, filiform corrosion and white bloom are finish problems that look like material problems. Anodizing and powder coating both perform excellently when specified for the actual environment, and both fail quickly when underspecified. Anodizing: architectural anodic film is normally 10-25 µm. Around 15-20 µm is typical for exterior work, and 20-25 µm is used in aggressive coastal or industrial atmospheres. Powder coating: architectural polyester powders are normally applied at 40-120 µm, with roughly 60-80 µm the common band for exterior building products. Coastal sites: move to a higher-performance powder system and specify stainless fasteners to avoid galvanic staining of the aluminum. Prevent dissimilar metal contact with isolating washers or coatings at every steel-to-aluminum interface. Remember that cut ends, drilled holes and site-cut profiles are unprotected unless touched up; specify a touch-up procedure. Problem 5: Glass, Screens and Hardware That Were Never Sized Together Cracked glass, sagging screens and hardware that loosens after a season usually means the glazing, screen and frame were specified independently. Glass panels sized for an indoor condition distort and crack in an exposed sunroom that sees direct summer sun and winter wind. Screen spline that is too small pulls out of the channel. Size glazing for the actual wind and thermal loads of the installation, not for an interior partition. Check that the glazing bite and gasket are deep enough to allow thermal movement. Match screen spline diameter to the extrusion's spline channel, and confirm the channel depth in the die drawing rather than on site. Use hardware rated for exterior use and match fastener material to the frame finish. The Point We pre-check beam deflection, knurl every thermal break profile, integrate drainage into the extrusion and match the finish to the site's actual environment. Send us your sunroom drawings and we will go through them with you, section by section, for strength, thermal performance, water management and finish durability.

=== 6063 vs. 6061 Aluminum: The Ultimate Guide to Properties, Performance, and Material Selection ===
URL: https://www.linkedalu.com/knowledge/6063-vs-6061-aluminum-the-ultimate-guide-to-properties-performance-and-material-selection.html
Published: 2026-05-21
The Quick Take Choose 6063 when the job is intricate cross-sections, thin walls and a flawless cosmetic surface: window and door frames, trim, louver blades, and heat sinks with dense fins. Choose 6061 when the profile carries real load and strength dominates: industrial framing, heavy-duty brackets, automotive components, machine bases and structural platforms. Both are magnesium-silicon 6000-series alloys, and the difference between them is entirely a matter of how much alloying element the mill is willing to add. Chemistry: Why Two Sibling Alloys Behave So Differently The ratio of alloying elements sets the boundaries of what the metal can do. The table below reflects the standard registered ranges for each alloy. Element 6063 6061 Practical effect Silicon (Si) 0.20-0.60% 0.40-0.80% Silicon binds magnesium into Mg2Si precipitates, the source of strength after ageing Magnesium (Mg) 0.45-0.90% 0.80-1.20% 6061 carries nearly twice the magnesium, driving yield strength and hardness up Iron (Fe) 0.35% max 0.70% max 6063 caps iron tightly to keep the extruded surface smooth and streak-free Copper (Cu) 0.10% max 0.15-0.40% Copper strengthens 6061 but slightly reduces corrosion resistance and anodized brightness Aluminum (Al) Balance Balance Both are aluminum-dominant; performance differences come from the traces above Mechanical Properties in the Tempers You Will Actually Buy T5 means the profile is cooled from the press and then artificially aged, with no separate solution treatment. T6 means it is solution heat treated and then artificially aged, which costs more and yields more. T66 is a tighter European temper specified with higher guaranteed minimums than ordinary T6 for the same alloy. Property 6063-T5 6063-T6 6061-T6 Tensile strength (min) 160 MPa 205 MPa 290 MPa Yield strength (min) 110 MPa 180 MPa 240 MPa Elongation (min) 8% 8% 8-10% Typical use Architectural frames, trim, heat sinks Loaded frames, railings, structural trim Machine framing, brackets, vehicle structures The headline is simple: 6061-T6 offers roughly 80 percent more tensile strength than 6063-T5, and about 40 percent more than 6063-T6. That is why structural engineers reach for it, and why extruders sometimes wince when they do. Extrudability and Design Freedom 6063 flows, 6061 resists 6063 has excellent hot fluidity. It extrudes into complex, multi-cavity and thin-walled hollow sections at high speed, which is why essentially every architectural window, door and curtain wall system in the world is built on it. 6061 deforms with much more resistance, so the press runs slower, hollow dies are more prone to welding-chamber problems, and thin webs on complex shapes crack more easily. Surface finish and anodizing response Because 6063 limits iron and is essentially copper-free, its anodic film stays clear, bright and uniform. 6061, with more iron and copper, tends to anodize to a slightly duller gray and is far less forgiving of small chemistry variations in the billet. If the component will be visible and anodized, that difference usually decides the material question on its own. Weldability Both alloys weld reliably with TIG or MIG processes. The difference is what happens afterwards: the heat-affected zone of 6061-T6 loses a large part of its strength and often needs post-weld heat treatment to recover it, while 6063 welds cleanly and is routinely used for low-stress decorative framing without any post-weld treatment. Corrosion, Machining and Cost 6063's near-zero copper content gives it excellent corrosion resistance in normal exterior service. 6061 loses a little of that margin because of its copper addition, but remains entirely suitable for exterior structural work with an appropriate finish. Where 6061 wins clearly is machining: its higher hardness produces cleaner chips, better surface finish off the cutter, and tighter achievable tolerances on secondary operations. Cost works against 6061 in two ways. Its billet typically carries a premium of roughly 10 to 15 percent over 6063, and because it extrudes more slowly it also costs more per meter to produce and is harder on dies. For high volumes of complex profiles, that gap is real money. Which Alloy for Which Job Application Sensible default Window and door frames, architectural trim 6063-T5 Visible anodized louvers and facades 6063-T5 or 6063-T6 LED and power electronics heat sinks 6063-T5 with dense fin geometry Solar mounting rails and structural railings 6005A-T5, or 6063-T6 for lighter loads Truck bodies, trailer frames, welded structures 6061-T6 or 6005A-T6 Industrial machine framing and brackets 6061-T6 Practical Selection Rules Start with 6063-T5 and step up only when a deflection or stress calculation says you must. If the section is complex and thin-walled, prefer a stronger temper of an easy-extruding alloy over a switch to 6061. If the part is welded and structural, check the as-welded properties, not the parent-metal properties. If the visible finish is anodized and color-critical, keep iron and copper low across the whole order, not just the first billet. If the profile is mostly machined afterwards, weight 6061's better machinability against its billet and extrusion cost. Frequently Asked Questions Is 6061 stronger than 6063 in every temper? Yes. Even 6061-T4 condition exceeds 6063-T6 in yield strength, and 6061-T6 is stronger than any commercially common 6063 temper. The trade is always extrudability, surface quality and cost. Can I mix 6063 and 6061 in one assembly? You can, and it is common. Keep dissimilar-metal contact in mind where moisture is present, and be aware that the two alloys respond differently to anodizing, so color matching between them is imperfect. Does 6061 need a different die? Usually yes in practice: bearing lengths, extrusion speed and quenching are all adjusted, and many plants keep separate tooling philosophy for 6061 work rather than pushing 6063 dies harder.