7005-T6 Aluminum
A copper-free 7000-series Al-Zn-Mg alloy, for welded extrusions
Typical values for the temper in the title
7005 is a copper-free zinc-magnesium alloy, like 7020, so it can be welded. In T6 its tensile strength is about 350 MPa, more than 6061.
It is best known from welded bicycle frames, and is also used for welded extrusions for rail and structures. It too regains strength by natural aging after welding.
Mechanical and physical properties
| Property | Value | Note |
|---|---|---|
| Tensile strength Rm | 350 MPa | |
| Yield strength Rp0.2 | 290 MPa | |
| Elongation A | 12% | |
| Hardness | 95 HB | |
| Modulus of elasticity E | 72 GPa | |
| Density ρ | 2.78 g/cm³ | |
| Machinability | 70% | relative rating in the site database |
Chemical composition (wt %)
| Element | Range | Role |
|---|---|---|
| Zn zinc | about 4.5 (nominal) | strengthening |
| Mg magnesium | about 1.4 (nominal) | strengthening |
| Mn manganese | about 0.45 (nominal) | controls the grains |
| Zr zirconium | about 0.14 (nominal) | controls the grains |
| Cr chromium | about 0.13 (nominal) | |
| Ti titanium | about 0.04 (nominal) | |
| Al aluminum | balance |
Common tempers
7005 is supplied mostly as extrusions and tubes in the T5 and T6 tempers.
| Temper | Properties | When to choose it |
|---|---|---|
| T5 | slightly lower strength | cooled from extrusion and aged |
| T6 | Rm ≈ 350 MPa, Rp0.2 ≈ 290 MPa | maximum strength |
| T53 | aged after extrusion | extrusions |
Applications
- Welded bicycle frames
- Welded extrusions for rail and vehicles
- Welded structures of medium-high strength
- Structural tubes and profiles
- Sports parts
Fabrication
Welding
Welds well, usually with ER5356 filler. After welding, the heat-affected zone regains strength by natural aging. Quality frames are also artificially aged after welding.
Extrusion
Extrudes well into tubes and profiles.
Corrosion
More susceptible than 6061 to stress corrosion cracking. Controlled welding and heat-treatment procedures matter.
Compared with similar materials
| Material | Rm / Rp0.2 | Welding | When it is the better choice |
|---|---|---|---|
| 6061-T6 | 310 / 276 MPa | Good — ER4043 | more available and more corrosion resistant, at lower strength · material page |
| 7020-T651 | 350 / 280 MPa | Excellent — ER5356 | another weldable 7000-series alloy, common in Europe · material page |
| 7003-T6 | 380–400 / 340–360 MPa | Excellent — ER5356 | another alternative for welded extrusions · material page |
Common mistakes
Testing a welded structure right after welding
Strength in the weld zone keeps rising for weeks. An early test will give low values.
Ignoring stress corrosion susceptibility
Uncontrolled welding and heat-treatment procedures raise the risk.
Replacing 6061 with 7005 without changing the welding procedure
The behavior after welding differs. A suitable procedure is needed.
Equivalents, standards and supply
| EN | EN AW-7005 (AlZn4.5Mg1.5Mn) |
|---|---|
| Standards | ASTM B221 / EN 755-2 |
| Forms | extrusion · rod · pipe |
| Producers | Hydro · Constellium · Aleris · Alcoa |
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