Dimensions
Critical dimensions, straightness and twist are checked on first articles and by sampling. Precision tolerances can be roughly half of the general tables on small sections.
Architectural-grade extrusions for vehicles
6063 T4, T5, T6, T64 and T66 Aluminium Automotive Profiles
6063 is the most widely extruded aluminium alloy in the world, valued for its smooth surface, fine detail and excellent anodising response. In vehicles it is used for trim, roof rails, window frames, interior structures, seat and console frames, tubes and cooling profiles, wherever moderate strength and a high-quality finish are needed. Metline supplies 6063 profiles and tubes to drawing in all standard tempers, cut, machined, bent and finished, to customers worldwide.
- Alloy
- 6063 (UNS A96063, EN AW-6063)
- Tempers
- T4, T5, T52, T6, T64, T66
- Min. yield (T6)
- 160 – 170 MPa
- Standards
- ASTM B221 · EN 755-2 · EN 12020
Why 6063 is used for automotive profiles
6063 contains just enough magnesium and silicon to give useful strength after ageing while staying soft at extrusion temperature. Billets can be pushed through intricate dies at high speed, and the low iron content produces a smooth, uniform surface that anodises bright and evenly. That is why 6063 dominates window and façade profiles, and why the same qualities make it popular for visible and complex vehicle parts.
On a car or commercial vehicle, 6063 appears in exterior trim and roof rails, window channels and sunroof frames, interior trim strips, seat-track covers and console frames, and in thin-finned cooling profiles for battery modules and power electronics. It is also widely used for drawn and extruded tube in air, coolant and auxiliary lines.
Its limitation is strength: 6063-T6 has a minimum yield of about 170 MPa, roughly 30 % below 6061-T6. For crash, chassis and battery-frame members, designers move to 6005A, 6061 or 6082. For decorative parts that also carry modest loads, the high-strength T66 temper often closes the gap without changing alloy.
6063 chemical composition (wt %)
Limits are the registered Aluminum Association values, matched by EN 573-3 for EN AW-6063 (AlMg0,7Si). Extruders often aim for the lower half of the range for decorative anodising and the upper half when T6 or T66 strength is needed.
| Element | Minimum | Maximum | Role |
|---|---|---|---|
| Silicon (Si) | 0.20 | 0.6 | Forms Mg2Si with magnesium |
| Iron (Fe) | — | 0.35 | Kept low for bright anodising |
| Copper (Cu) | — | 0.10 | |
| Manganese (Mn) | — | 0.10 | |
| Magnesium (Mg) | 0.45 | 0.9 | Main strengthening element |
| Chromium (Cr) | — | 0.10 | |
| Zinc (Zn) | — | 0.10 | |
| Titanium (Ti) | — | 0.10 | Grain refiner |
| Others, each / total | — | 0.05 / 0.15 | |
| Aluminium (Al) | Remainder | About 97.5 – 99.4 % |
Some tables list silicon from 0.10 % or zinc to 0.13 %; the registered limits are 0.20 – 0.6 % Si and 0.10 % Zn maximum.
Mechanical properties of 6063 profiles
Specified minimums for extruded profiles from EN 755-2. ASTM B221 gives similar values: 6063-T5 at 150 MPa tensile and 110 MPa yield, and 6063-T6 at 205 MPa and 170 MPa.
| Temper | Wall thickness (mm) | Rm min (MPa) | Rp0.2 min (MPa) | A / A50 min (%) | Typical hardness (HBW) |
|---|---|---|---|---|---|
| T4 | ≤ 25 | 130 | 65 | 14 / 12 | 50 |
| T5 | ≤ 3 | 175 | 130 | 8 / 6 | 65 |
| T5 | > 3 – 25 | 160 | 110 | 7 / 5 | 65 |
| T6 | ≤ 10 | 215 | 170 | 8 / 6 | 75 |
| T6 | > 10 – 25 | 195 | 160 | 8 / 6 | 75 |
| T64 | ≤ 15 | 180 | 120 | 12 / 10 | 65 |
| T66 | ≤ 10 | 245 | 200 | 8 / 6 | 80 |
| T66 | > 10 – 25 | 225 | 180 | 8 / 6 | 80 |
Physical properties (T5 / T6, typical)
- Density
- 2.69 – 2.70 g/cm³
- Modulus of elasticity
- about 69 GPa
- Thermal conductivity
- about 200 – 209 W/m·K
- Electrical conductivity
- about 53 – 55 % IACS
- Coefficient of thermal expansion
- 23.4 µm/m·°C (20 – 100 °C)
- Melting range
- about 615 – 655 °C
Choosing a 6063 temper
| Temper | Process | Best for |
|---|---|---|
| T4 | Solution treated, naturally aged | Stretch-bent or roll-formed parts that are aged afterwards |
| T5 | Press-quenched, artificially aged | Everyday trim and frames; lowest cost |
| T52 | Press-quenched, stress-relieved and aged to a lower strength | Parts needing extra ductility and low residual stress |
| T6 | Solution treated and fully aged | Interior structures, rails and tubes carrying light loads |
| T64 | Under-aged | Curved roof rails and window frames |
| T66 | Controlled chemistry, fully aged | Highest-strength 6063 for lightly loaded structures |
Profile and tube range
Typical 6063 automotive range
- Profiles
- Open, semi-hollow and multi-cavity hollow sections to drawing
- Tube
- Round, square, rectangular and oval tube; drawn tube for tighter tolerances
- Wall thickness
- From about 0.5 – 0.8 mm on small sections; 1 – 5 mm common
- Section width
- About 10 – 250 mm for most automotive trim and frames
- Length
- Mill lengths about 3 – 7 m, or cut to finished length
- Finishes
- Bright, satin or coloured anodising, anodising plus electrocoat, powder coat, paint, brushing, polishing
- Processing
- Cutting, CNC machining, punching, stretch bending, end forming of tubes
Tolerances and surface quality
For trim and frames that seal against glass or paint, EN 12020-2 precision tolerances are usually specified instead of the general EN 755-9 tables. For US programmes, ANSI H35.2 tolerances apply through ASTM B221.
Decorative surface
Mark the visible faces on the drawing; die lines, pick-up and handling marks are controlled on those faces.
Anodising
Film thickness class (for example 10, 15 or 20 µm), colour range and seal quality to EN ISO 7599 or Qualanod.
Bending
For stretch-bent rails, agree the temper, elongation and any T4 shelf-life limit with the bender.
Where 6063 profiles are used in vehicles
- Exterior trim: roof rails, window surrounds, belt-line mouldings and grille surrounds, often bright anodised
- Glazing and sunroof: sunroof frames, guide rails and window channels
- Interior: door and dashboard trim strips, seat-track covers, console and armrest frames
- Thermal management: cooling plates, fin profiles and electronics housings for EV batteries and inverters
- Tubes: air, coolant and auxiliary lines, handrails and grab bars in buses and coaches
- Commercial bodies: van and caravan frames, luggage racks and door frames
6063 is not used for brake calipers, steering knuckles or suspension arms, despite claims in some trade literature. Those are forged or cast parts in stronger alloys.
6063 compared with 6060, 6463 and 6061
| Property | 6063-T6 | 6060-T6 | 6463-T6 | 6061-T6 |
|---|---|---|---|---|
| Rp0.2 min (thin wall) | 170 MPa | 150 MPa | about 170 MPa | 240 MPa |
| Extrudability | Excellent | Excellent | Excellent | Fair–good |
| Bright finish | Very good | Very good | Excellent (bright-dip alloy) | Good |
| Typical use | Trim, frames, tubes | Trim, cooling profiles | Bright trim | Structural members |
For mirror-bright trim after chemical brightening, 6463 is the specialist choice. For a small strength increase, use 6063-T66; for structural loads, move to 6061 or 6005A.
How to order 6063 profiles from Metline
- SpecifySection drawing, alloy and temper (e.g. 6063-T6), length, finish and colour, decorative faces, machining or bending requirements, and annual volume.
- Confirm the standardASTM B221 or EN 755-2 for properties, and EN 12020-2, EN 755-9 or your drawing for tolerances.
- QuoteWe confirm availability, tolerances, certification and delivery terms (EXW, FOB, CIF or DAP) for your plant or port.
- Process and inspectProfiles are checked, finished, protected with film or interleaving and packed to prevent rubbing marks in transit.
- 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
- ASTM B221 – Aluminum and Aluminum-Alloy Extruded Bars, Rods, Wire, Profiles, and Tubes
- EN 755-2 – Extruded rod/bar, tube and profiles: mechanical properties
- EN 12020-2 – Extruded precision profiles in alloys EN AW-6060 and EN AW-6063: tolerances on dimensions and form
- ANSI H35.2 – Dimensional Tolerances for Aluminum Mill Products
- The Aluminum Association – International Alloy Designations and Chemical Composition Limits (Teal Sheets)
6063 aluminium (aluminum) automotive profiles: frequently asked questions
How strong is 6063-T6?
EN 755-2 requires 215 MPa tensile and 170 MPa yield for walls up to 10 mm; ASTM B221 requires 205 MPa and 170 MPa. Typical values are around 240 MPa tensile and 215 MPa yield.
What is 6063-T66?
A T6 temper produced with controlled chemistry and processing to reach higher minimums, 245 MPa tensile and 200 MPa yield in walls up to 10 mm.
Is 6063 good for anodised car trim?
Yes. Its low iron and fine structure give an even anodised finish, which is why it is widely used for roof rails and window trim. For mirror-bright finishes, 6463 is also used.
Can 6063 be used for structural vehicle parts?
Only lightly loaded ones, such as interior frames and racks. For crash members, sub-frames and battery frames, use 6005A, 6061 or 6082.
Which temper is best for bending 6063?
T4 or T64, because they keep more elongation. The part can be aged after bending to recover strength.
Do you export 6063 profiles?
Yes. Metline supplies 6063 extrusions and tube worldwide with mill certificates and export packing on EXW, FOB, CIF or DAP terms.
Developing a 6063 trim or frame?
Send the drawing, temper, finish and volume. Our team will review feasibility and reply with tolerances and delivered pricing.
