T1
Cooled from the press and naturally aged. Low strength; used for parts that will be formed and aged later.
Structural automotive extrusions
6005 and 6005A Aluminium Profiles for Automotive
6005 and 6005A are medium-strength structural extrusion alloys that sit between 6063 and 6082: stronger than 6063, far easier to extrude into thin-walled hollow sections than 6082. That makes them a natural choice for vehicle frames, roof rails, battery-tray members, bus and trailer structures. Metline supplies 6005 and 6005A profiles to drawing in T4, T5 and T6, certified to EN 755 and ASTM B221, worldwide.
- Alloys
- 6005, 6005A (EN AW-AlSiMg(A))
- Tempers
- T1, T4, T5, T6
- T6 yield
- ≥ 215 – 225 MPa (EN 755-2)
- Standards
- EN 755 · ASTM B221
Where 6005 and 6005A fit in vehicle design
Automotive extrusions fall into three broad strength classes. 6060 and 6063 are easy to extrude and finish but modest in strength. 6082 and 6061 are strong but extrude slowly and struggle with thin walls and complex hollows. 6005 and 6005A fill the gap: they reach a T6 proof stress of more than 200 MPa while still running through multi-cavity hollow dies at reasonable speeds.
6005 is the original Aluminum Association alloy with tight limits on copper, manganese and chromium. 6005A, the European variant, allows more manganese, chromium and copper. Those additions control grain structure and raise toughness, which helps crash and fatigue performance, and they make 6005A slightly less sensitive to quench rate in thicker walls. In practice 6005A is the more common choice in Europe and in automotive platforms, while 6005 appears more often in North American specifications.
Both alloys can be press-quenched with air or water mist at the extrusion press exit and then artificially aged (T5), avoiding a separate solution heat-treatment step for thin and medium walls. Thicker or heavily loaded parts are solution-treated and aged to full T6.
6005 and 6005A chemical composition (wt %)
Registered limits per the Aluminum Association and EN 573-3. The difference between the two is mainly the allowance for manganese, chromium and copper.
| Element | 6005 | 6005A |
|---|---|---|
| Silicon (Si) | 0.6 – 0.9 | 0.50 – 0.9 |
| Magnesium (Mg) | 0.40 – 0.6 | 0.40 – 0.7 |
| Iron (Fe) | 0.35 max | 0.35 max |
| Copper (Cu) | 0.10 max | 0.30 max |
| Manganese (Mn) | 0.10 max | 0.50 max |
| Chromium (Cr) | 0.10 max | 0.30 max |
| Mn + Cr | — | 0.12 – 0.50 |
| Zinc (Zn) | 0.10 max | 0.20 max |
| Titanium (Ti) | 0.10 max | 0.10 max |
| Others, each / total | 0.05 / 0.15 | 0.05 / 0.15 |
| Aluminium (Al) | Remainder | Remainder |
Mechanical properties by temper
EN 755-2 values below are specified minimums for 6005A profiles; they depend on wall thickness and on whether the section is open or hollow. ASTM B221 values for 6005-T5 are shown for comparison.
| Temper and section | Tensile Rm min | Proof Rp0.2 min | Elongation A min |
|---|---|---|---|
| 6005A-T4, wall ≤ 25 mm | 180 MPa | 90 MPa | 15 % |
| 6005A-T6 open profile, ≤ 5 mm | 270 MPa | 225 MPa | 8 % |
| 6005A-T6 open profile, > 5 – 10 mm | 260 MPa | 215 MPa | 8 % |
| 6005A-T6 open profile, > 10 – 25 mm | 250 MPa | 200 MPa | 8 % |
| 6005A-T6 hollow profile, ≤ 5 mm | 255 MPa | 215 MPa | 8 % |
| 6005A-T6 hollow profile, > 5 – 15 mm | 250 MPa | 200 MPa | 8 % |
| 6005-T5 (ASTM B221), ≤ 12.5 mm | 262 MPa (38 ksi) | 241 MPa (35 ksi) | 8 % |
Always confirm the exact limits for your wall thickness on the order; values above summarise EN 755-2 and ASTM B221.
Physical properties (T6)
- Density
- 2.70 g/cm³
- Modulus of elasticity
- about 69 GPa
- Thermal conductivity
- about 180 – 190 W/m·K
- Electrical conductivity
- about 47 – 49 % IACS
- Coefficient of thermal expansion
- about 23.5 µm/m·°C
T1, T4, T5 or T6: choosing the temper
T4
Solution treated and naturally aged. Softer and more ductile for bending and hydroforming, then aged to T6.
T5
Press-quenched and artificially aged. Saves a furnace step; suitable for thin and medium walls where the press quench is fast enough.
T6
Separately solution treated, quenched and aged. Highest guaranteed strength, used for thicker walls and critical structural parts.
T64 / T66 variants
Some vehicle makers specify under- or controlled-aged conditions to balance strength and crush behaviour. These are agreed on the drawing.
Post-forming age
Parts bent in T4 can be aged after forming, often combined with the paint-bake cycle for part of the strength gain.
6005 and 6005A profile sizes
6005 / 6005A profile supply range
- Sections
- Custom open, semi-hollow and hollow (multi-cavity) profiles to drawing
- Standard shapes
- Round, square and rectangular tube, angle, channel, T and flat bar
- Size
- Circumscribing circle from small trim sections up to large structural profiles; wall typically 1.5 mm and up
- Length
- Usually cut 3 – 6 m, or precision cut to part length
- Tempers
- T1, T4, T5, T6 and customer-specified ageing
- Surface
- Mill finish, anodised, e-coated or powder coated on request
- Processing
- Precision sawing, CNC machining, punching, bending and stretch-bending on request
The achievable section depends on the die and the alloy's extrudability; send a drawing so we can confirm wall, tolerance and length.
Common standard shapes such as 20 × 20, 30 × 30 and 40 × 40 mm square tube or angle in 1 – 3 mm wall are useful for prototypes and secondary structures, but most automotive work uses custom sections designed for the vehicle. Weight per metre equals cross-sectional area (cm²) × 0.27 kg; a 40 × 40 × 2 mm square tube, for example, weighs about 0.82 kg/m.
Welding, bending and finishing
Welding
MIG and TIG with ER4043 or ER5356 filler; friction-stir welding is widely used for battery-tray floors. Expect the heat-affected zone to drop to roughly T4-level strength in the as-welded state.
Bending
Bend in T4 for tight radii and age afterwards, or use stretch-bending for large-radius roof rails. Hollow sections need mandrels or filler to prevent wall collapse.
Machining
Machines cleanly in T5/T6 with sharp carbide tools. CNC machining of mounting faces and holes is routine.
Joining to steel
Isolate from steel with coatings, sealants or insulating washers; use self-piercing rivets or flow-drill screws for mixed joints.
Finishing
Accepts anodising, e-coating and powder coating. Mill-finish parts inside a painted body are e-coated with the body.
Corrosion
Good general corrosion resistance. Copper is low enough in 6005 and 6005A that filiform and intergranular attack are rarely a problem under paint.
Automotive uses of 6005 and 6005A
| Part | Typical temper | Why this alloy |
|---|---|---|
| Battery-tray frames and cross members | T6 | Multi-cavity hollows with good strength and weldability |
| Roof rails and side rails | T5 / T6 | Long, thin-walled sections; stretch-bendable |
| Bus and coach body frames | T6 | Welded structural tubes at lower cost than 6082 |
| Truck and trailer side rails, floor beams | T5 / T6 | Large sections extruded economically |
| Seat rails and cargo management | T5 | Good surface for anodising or painting |
| Subframe and bumper-system members | T6 / agreed ageing | Strength with controlled crush behaviour |
A typical EV battery enclosure combines 6005A-T6 multi-cavity side members with friction-stir-welded floor profiles. The alloy is chosen because it extrudes thin internal webs reliably while giving the frame enough strength for side-impact loads.
6005A compared with 6063, 6061 and 6082
| Property | 6063-T6 | 6005A-T6 | 6061-T6 | 6082-T6 |
|---|---|---|---|---|
| Typical yield | about 215 MPa | about 240 – 250 MPa | about 275 MPa | about 280 – 300 MPa |
| Extrudability | Excellent | Very good | Fair | Fair |
| Thin-walled hollows | Excellent | Very good | Limited | Limited |
| Weldability | Good | Good | Good | Good |
| Anodised appearance | Excellent | Good | Good | Fair |
| Relative cost to extrude | Lowest | Low | Higher | Higher |
If a 6063 section is too weak, 6005A is usually the first step up before moving to 6082 or 6061. If you need still more strength in a crash-relevant hollow, consider 6008 or a 7xxx alloy such as 7003.
How to order 6005 / 6005A profiles
- SpecifyAlloy (6005 or 6005A), temper, section drawing with critical dimensions, length, surface finish, tolerances and annual volume.
- Confirm the standardEN 755-2 / EN 755-9 (profiles) or EN 12020 for precision sections, ASTM B221, or the vehicle maker's specification.
- QuoteWe confirm availability, tolerances, certification and delivery terms (EXW, FOB, CIF or DAP) for your plant or port.
- Process and inspectProfiles are cut, machined if required, checked for dimensions, straightness and twist, and packed with separators to protect the surface.
- Document and shipEach lot ships with an EN 10204 3.1 mill test certificate, lot traceability and a packing list, in seaworthy export packing. Third-party inspection can be arranged on request.
References and standards
- EN 755-2 – Extruded rod/bar, tube and profiles: mechanical properties
- EN 755-9 – Extruded rod/bar, tube and profiles: profiles, tolerances on dimensions and form
- ASTM B221 – Aluminum and Aluminum-Alloy Extruded Bars, Rods, Wire, Profiles, and Tubes
- EN 573-3 – Aluminium and aluminium alloys: chemical composition and form of wrought products
- The Aluminum Association – International Alloy Designations and Chemical Composition Limits (Teal Sheets)
6005 and 6005A automotive profiles: frequently asked questions
What is the difference between 6005 and 6005A?
6005A allows more manganese, chromium and copper (Mn + Cr 0.12 – 0.50 %). That refines grain structure and improves toughness and quench tolerance. Strength is similar; 6005A is more common in Europe and in vehicle platforms.
Is 6005A stronger than 6063?
Yes. In T6, 6005A open profiles up to 5 mm wall have a minimum proof stress of 225 MPa under EN 755-2, against about 170 MPa for 6063-T6, while still extruding thin-walled hollows well.
Can 6005A replace 6082 in automotive frames?
Often, yes, for thin-walled hollows where 6082 is hard to extrude. 6082 remains stronger in thick sections, so check the design loads before substituting.
What does T5 mean for 6005 aluminum extrusions?
T5 means the profile is quenched at the press exit and then artificially aged, without a separate solution heat treatment. It suits thin and medium walls and reduces cost.
Is 6005A suitable for EV battery trays?
Yes. It is widely used for battery-tray side members and floor profiles because it extrudes complex multi-cavity sections and welds well, including by friction-stir welding.
What documentation do you provide?
An EN 10204 3.1 mill test certificate with chemistry and tensile results for each lot, plus dimensional reports and PPAP-style documents on request.
Need 6005A profiles for a vehicle program?
Send the drawing, temper and annual volume. Our team will reply with feasibility, certification and a delivered price.
