Aluminum 6082 - B221 6082 - EN AW-AlSi1MgMn - EN AW-6082

Where does 6082 aluminium come from? Positioning versus 6061

6082 is an European-origin aluminium alloy, derived from historical designations such as AlMgSi1 (German) and HE30 (British). It belongs to the wrought Al-Mg-Si alloy family (6000 series).

In common structural applications, a fairly stable market pattern can be observed.

• In Europe, 6082 is often the reference grade for engineering parts and products in the 6000 series.
• In North America, 6061 is more common as a functional equivalent across many supply chains.

As a result, heat-treated plates are widely available in 6061-T651 in some supply channels, which naturally influences material selection when immediate availability is the priority.

There is, however, one notable exception: high-performance wheels, including in Europe. In that sector, 6061-T6 is often preferred, driven by US influence and long-established supply chain habits.

How do the alloying elements in 6082 affect its performance?

The full chemical composition of 6082 is detailed later in this article.

6082 belongs to the Al-Mg-Si alloy family, whose mechanical performance relies on precipitation hardening. In practical terms:

• After solution heat treatment, quenching, and then ageing, the alloy forms very fine precipitates that strengthen its internal structure.
• The magnesium + silicon combination enables the formation of these precipitates and limits deformation of the metal.
• A slight excess of silicon can improve the response to ageing and help achieve higher mechanical strength.

Manganese (Mn) plays a stabilising role, particularly through grain size control. It helps homogenise the structure, improving mechanical consistency and the uniformity of properties.

Metallurgical tempers and heat treatments

The behaviour of 6082 depends as much on its chemistry as on the thermal sequence applied to it. The most useful process settings can be summarised in four key stages.

Table - 6082 heat treatment windows

Impact of temper: from annealed (O) to hardened (T6)

For sheets and plates, the metallurgical temper directly controls four key indicators: ultimate tensile strength Rm, yield strength Rp0.2, elongation at fracture A, and Brinell hardness HBS.

Table - Performance by temper (sheets / plates)

Note: for T6, Rp0.2 drops from ≥ 260 MPa (up to 6 mm) to ≥ 255 MPa (from 6 to 12.5 mm); HBS is approximately 94, then 91. The table above keeps the most conservative values, i.e. the guaranteed minimum values.

Numerical summary (same product form, e = 0.4-1.5 mm): these differences clearly show the “price to pay” for hardening: strength increases significantly, but elongation decreases.

• From O → T451: ΔRm +55 MPa, ΔRp0.2 +25 MPa, ΔA −2%, ΔHBS +18.
• From O → T6: ΔRm +160 MPa, ΔRp0.2 +175 MPa, ΔA −8%, ΔHBS +54.

The bending radii given below (90°) are expressed as multiples of thickness e.

Table - Bending guide (minimum inside radii at 90°) (sheets / plates)

Treatment sensitivity: T6 vs T5 (test data)

Laboratory tests (see graph below) reveal a fundamental difference in behaviour between T5 temper (cooled after forming) and T6 temper (optimised quenching and ageing).

This graph highlights the classic strength / ductility trade-off of 6082 depending on the temper. The T6 points shift towards higher Rm values (≈ 352-384 MPa), at the cost of lower elongation (≈ 9-15%), with the most severe ageing conditions around 190 °C. By contrast, the T5 conditions remain more ductile (≈ 14-15%) but are limited to more modest Rm values (≈ 325-333 MPa).

What mechanical properties can be expected depending on product form and thickness, at constant temperature (20 °C)?

Mechanical properties of rolled products (sheets and plates)

For flat products (sheets, plates, strips), mechanical properties are not constant: they decrease as thickness increases.

Table - EN 485-2: minimum 6082 properties by thickness (T6 / T651 / T62)

Properties of extrusions: bars, tubes and profiles

Unlike sheets, long products (bars and profiles) follow a different logic. Their properties depend not only on thickness, but also on the manufacturing route: extruded (pressed) or drawn.

The overall trend is straightforward: thin sections (wall thickness ≤ 5 mm) already show high minimum values, while thicker walls (up to 25 mm) generally achieve higher Rp0.2 and A values.

Table - Guaranteed minimum values for T6 extrusions (bars / tubes / profiles)

How does temperature affect 6082 aluminium?

Unlike steel, aluminium loses its mechanical properties quickly as temperature rises. For 6082-T6, a reasonable upper limit for structural use is around 150 °C to 170 °C. The data in the graph below come from tests carried out at a constant strain rate, after a 30-minute holding time at the target temperature.

This graph shows the reduction factors for the properties of 6082-T6 at elevated temperature (reference: 20 °C). The yield strength (Rp0.2) and ultimate tensile strength (Rm) drop rapidly as temperature rises, while the Young's modulus E remains relatively close to its initial value up to around 250 °C before falling sharply. The 50% marker illustrates a practical threshold: Rp0.2 falls below half of its room-temperature value at about 240 °C, which marks a major loss of load-bearing capacity in the danger zone.

Welding 6082: hot cracking and loss of strength

Welding 6082 requires two major precautions: selecting the correct filler wire to avoid hot cracking, and accounting for the sharp drop in mechanical properties in the welded area.

Hot cracking risk: choosing the right filler metal

6082 is sensitive to cracking during weld pool solidification. Laboratory tests (Houldcroft method) show that 6082 should never be welded without filler metal (autogenous welding), nor with an unsuitable filler wire.

Test results (filler wire comparison)

Heat-affected zone (HAZ): strength loss

Even when the weld itself is sound, the heat input locally destroys the T6 heat treatment around the weld bead. The metal therefore returns towards a much softer condition.

According to Eurocode 9, this loss is very significant. As an order of magnitude, for 6082-T6, depending on product form and thickness, designers typically retain:

• Yield strength (Rp0.2): about 48 to 52% of the original value.
• Ultimate tensile strength (Rm): about 60% of the original value.