Metal
Aluminum 7075 properties
7075-T6 is a zinc-alloyed aerospace aluminum with 572 MPa tensile and 503 MPa yield strength at a density of 2.81 g/cm³: close to double the yield of 6061 and higher than 304 stainless. The price of that strength is corrosion resistance and weldability. It pits in humid or salt air, is susceptible to stress corrosion cracking, and is effectively unweldable by conventional methods.
Published values for unfilled grades at 23 °C unless stated. Confirm against the supplier datasheet for the grade you specify.
What it is
7075 is a zinc-alloyed aluminum with roughly twice the yield strength of 6061, putting it in the range of medium-carbon steel while staying light. It is the standard choice for highly loaded machined structure in aerospace, motorsport, and robotics.
The cost is corrosion resistance and weldability. It is susceptible to stress corrosion cracking, and it is effectively unweldable by conventional methods.
7075 against steel, 6061 and titanium
7075 is not a steel, but it is often specified in place of one. The last column divides yield strength by density, so it shows how much load each kilogram of material carries. Figures are the typical values from each material's own page.
| Property | 7075-T6 | 6061-T6 | Stainless 304 | Titanium Grade 5 |
|---|---|---|---|---|
| Density | 2.81 g/cm³ | 2.70 g/cm³ | 8.00 g/cm³ | 4.43 g/cm³ |
| Tensile strength | 572 MPa | 310 MPa | 515 MPa | 950 MPa |
| Yield strength | 503 MPa | 276 MPa | 205 MPa | 880 MPa |
| Elongation | 11 % | 12 % | 40 % | 14 % |
| Hardness | 150 HB | 95 HB | 201 HB max | 334 HB |
| Relative cost | Medium | Low | Medium | Very high |
| Yield per unit density, calculated | 179 | 102 | 26 | 199 |
Read across, 7075 carries about seven times the yield load of 304 stainless per kilogram and comes within about 10 % of titanium Grade 5 at a fraction of the cost. 304 is far more ductile (40 % elongation against 11 %) and far better in wet or salt environments, so it stays the choice where corrosion, not weight, decides.
Is 7075 corrosion resistant?
Less so than 6061. Bare 7075 pits in humid or salt environments, and sustained tensile stress in the short-transverse direction can start stress corrosion cracking. The usual protections are anodising, the overaged T7351 temper, which gives up some strength for much better stress corrosion resistance, or Alclad sheet with a pure aluminum cladding.
Where it is used
- Highly loaded structural brackets and frames
- Motorsport and aerospace machined components
- Robotics arms and joints
- Mold and die components where steel would be too heavy
- High-stress fixtures
Processing notes
Machines well but is harder on tooling than 6061, and it produces a stringier chip.
Do not design welded joints. Fasten or bond.
Anodise for corrosion protection; bare 7075 pits in humid or salt environments.
Available through
Design notes
Use it where the load justifies it. On a lightly loaded part it is simply a more expensive 6061.
Avoid sustained tensile stress in the short-transverse direction, which is where stress corrosion cracking starts.
T7351 temper trades some strength for much better stress corrosion resistance and is worth specifying on long-life parts.
Grades and variants
- 7075-T6, maximum strength
- 7075-T651, stress relieved plate
- 7075-T7351, overaged, better stress corrosion resistance
- Alclad 7075, pure aluminum cladding for corrosion protection
- 2024-T3, alternative high strength alloy with better fatigue life
Alternatives
If Aluminum 7075 is not the right answer
See the full Aluminum 6061 vs 7075 comparison, spec by spec.
Specifying this material?
Send your CAD and target volumes. We come back with a price, a lead time, and any material or design notes that would reduce either.