6061-T6 Aluminum
A 6000-series Al-Mg-Si alloy, the most common structural aluminum alloy in the world
Typical values for the temper in the title
6061 is a heat-treatable aluminum alloy whose strength comes from Mg₂Si precipitates formed during aging. In the T6 temper it reaches a typical tensile strength of 310 MPa, and it combines, unusually well, moderate strength, good corrosion resistance, weldability and good machinability.
That combination makes it the default whenever "structural aluminum" is needed: frames, fixtures, machine parts and extrusions. When it is not enough, the next choice is usually 7075 for strength, or 5083 for welded marine structures.
Mechanical and physical properties
| Property | Value | Note |
|---|---|---|
| Tensile strength Rm | 310 MPa | |
| Yield strength Rp0.2 | 276 MPa | |
| Elongation A | 12% | |
| Hardness | 95 HB | |
| Modulus of elasticity E | 68.9 GPa | |
| Density ρ | 2.71 g/cm³ | |
| Machinability | 90% | relative rating in the site database |
Chemical composition (wt %)
| Element | Range | Role |
|---|---|---|
| Mg magnesium | 0.8–1.2 | with silicon, forms the Mg₂Si precipitates that give the strength |
| Si silicon | 0.40–0.80 | part of the strengthening precipitates |
| Cu copper | 0.15–0.40 | adds some strength |
| Cr chromium | 0.04–0.35 | controls the grain structure |
| Fe iron | max 0.70 | |
| Mn manganese | max 0.15 | |
| Zn zinc | max 0.25 | |
| Ti titanium | max 0.15 | |
| Others | max 0.05 each, 0.15 total | |
| Al aluminum | balance |
Common tempers
6061 is supplied mostly as T6. The temper sets the strength, and above all the behavior in machining and welding.
| Temper | Properties | When to choose it |
|---|---|---|
| O (annealed) | soft and easy to form | for severe bending and forming, with heat treatment afterwards |
| T4 | Rm ≈ 241 MPa, Rp0.2 ≈ 145 MPa | naturally aged: easier to bend than T6, and can be aged to T6 later |
| T6 | Rm 310 MPa, Rp0.2 276 MPa | maximum strength, the most common temper |
| T651 | as T6 | T6 stretched to relieve stress (plate and bar): less distortion when machining |
Applications
- Frames, structures and chassis
- Fixtures, jigs and machine parts
- General extrusions, tubes and bars
- Marine fittings and structures in humid environments
- Bicycles and sports equipment
Fabrication
Machining
Machines well in the T6 temper. In O or T4 the material is soft, tends to smear and produces long chips, so it is better to machine T6 and use chip breakers. For precise parts, order T651 (stress relieved), which distorts less once it comes off the machine.
Welding
Welds well with TIG and MIG, usually with ER4043 or ER5356 filler. But in the heat-affected zone (HAZ) strength drops significantly, because the precipitates built during aging dissolve. Welded structures are therefore designed to the strength of the weld zone, or the part is fully heat treated again after welding.
Corrosion and protection
Good resistance to atmospheric corrosion and humid environments. Anodizes well, including hard anodizing (Type III), and takes paint and powder coating.
Compared with similar materials
| Material | Rm / Rp0.2 | Welding | When it is the better choice |
|---|---|---|---|
| 6082-T6 | 310 / 260 MPa | Good — ER4043 | the European alternative: similar composition and similar T6 strength, widely stocked in Europe and Israel · material page |
| 6063-T6 | 205–240 / 170–190 MPa | Good — ER4043 | for complex extrusions and surface finish, when strength matters less · material page |
| 7075-T6 | 503–572 / 434–503 MPa | Not recommended — FSW | when almost twice the strength is needed and no welding is required · material page |
Common mistakes
Designing a welded structure to T6 strength
The weld zone loses much of its strength. Calculations must be based on the strength of the weld zone.
Bending T6 to a tight radius
T6 cracks in sharp bends. For significant bending, O or T4 is better, followed by heat treatment.
Replacing 6061 with 6082 without checking
In most cases they are interchangeable, but the drawing or the standard may require 6061. A substitution needs approval.
Equivalents, standards and supply
| EN | 3.3211 |
|---|---|
| DIN | AlMg1SiCu |
| JIS | A6061 |
| Standards | ASTM B209 / EN 485-2 / AMS 2770 |
| Forms | plate · rod · extrusion · pipe |
| Producers | Novelis · Aleris · Constellium · Hydro · Alcoa · Kaiser |
Learn more
Values are typical and for comparison only. For design, rely on the standard and on the mill certificate. Sources: Aluminum Association (composition), ASM and MatWeb data sheets, and the METAL HUB materials database.
Updated: October 31, 2026