Alloy and Temper Definition
6082 is a heat-treatable Al-Mg-Si-Mn alloy and the highest-strength grade of the 6xxx family commonly used for structural extrusion. EN 573-3 defines the composition as 0.7-1.3% Si, 0.6-1.2% Mg and 0.40-1.0% Mn, with Fe limited to 0.50%, Cu to 0.10%, Cr to 0.25% and Zn to 0.20%. Manganese refines the grain structure and improves the balance between strength and toughness.
The T6 designation means solution heat treatment followed by artificial ageing. The temper gives the alloy its full design strength; it also means the material has limited remaining formability, so profiles are extruded and plate parts are machined or bent to generous radii before ageing, or ordered pre-aged and used as delivered.
Specification Framework
EN 755-2 states the mechanical properties of extruded bar, tube and profiles, and EN 485-2 covers sheet and plate. For structural use in buildings, EN 1999-1-1 - Eurocode 9, Part 1-1 - gives partial factors, buckling curves and the reduced strength values that apply in the heat-affected zone of welded connections. In China, GB/T 5237 covers wrought aluminium alloy extruded profiles for architecture, with GB/T 5237.2 for anodised, GB/T 5237.3 for electrophoretic, GB/T 5237.4 for powder coated and GB/T 5237.5 for fluorocarbon coated finishes.
Mechanical Properties
| Property | 6082-T6 extruded profile | 6082-T6 plate |
|---|---|---|
| Tensile strength (min, EN 755-2 / EN 485-2) | 310 MPa | 290 MPa |
| Yield strength 0.2% (min) | 260 MPa | 250 MPa |
| Elongation (min) | 8-10% | 6-8% |
| Typical as-produced values | about 340 MPa / 310 MPa | about 310 MPa / 280 MPa |
| Density | 2.70 g/cm3 | 2.70 g/cm3 |
| Hardness | about 95-100 HB | about 95 HB |
Comparison with 6061 and Selection Guidance
6082 and 6061 share the same strengthening system, but 6082 carries a slightly higher minimum proof stress in extruded form and is the customary choice for European structural profiles; 6061 dominates North American practice. Where a building standard requires declared design values for an extruded profile, 6082-T6 with EN 755-2 property certification is the more direct route, and its extrudability supports the thin, complex wall sections used for curtain wall mullions and transoms.
Fabrication and Finish
Profiles are extruded to tight dimensional tolerance and can be supplied with integrated screw ports and thermal breaks. Welding uses 5356 or 4043 filler; strength in the heat-affected zone must be reduced per EN 1999-1-1 unless the joint is re-aged. Finishes follow the GB/T 5237 parts listed above, with coating thickness verified by the tests specified in each part. For load-bearing applications the alloy is normally supplied with a 3.1 inspection certificate.
Frequently Asked Questions
Q: What is the minimum yield strength of 6082-T6 extruded profile?
A: EN 755-2 specifies 260 MPa 0.2% proof stress for profiles of 5-25 mm wall thickness, with tensile strength of 310 MPa minimum.
Q: Can 6082-T6 be bent after ageing?
A: Only to large radii; bending is normally performed in the T4 temper followed by artificial ageing to T6, or by stretch forming with tooling that controls springback.
Q: Is 6082-T6 suitable for load-bearing building elements?
A: Yes. It is the reference alloy for European structural aluminium, provided design is carried out to EN 1999-1-1 and welded zone properties are applied correctly.
Q: Which finish standards apply to architectural profiles?
A: GB/T 5237 Parts 2 to 5 cover anodised, electrophoretic, powder coated and fluorocarbon coated finishes, each with its own coating performance tests.
Q: How does 6082-T6 plate differ from extruded profile in strength?
A: Rolled plate carries slightly lower guaranteed minima than extruded profile - 290 MPa tensile and 250 MPa proof stress - because of the different thermomechanical route.