What is aluminium 7075?
7075 is a high-strength aluminium alloy developed in the 1930s to meet the demand for lightweight structural materials in aircraft manufacturing. Today, it remains one of the strongest commercially available aluminium grades, with zinc as its primary alloying element. The aerospace-approved equivalent in the UK is L95.
7075 is widely used in high-performance applications where strength and fatigue resistance are critical, and where corrosion resistance is a secondary consideration. L95 is commonly specified for aerospace, defence, and nuclear sectors where components operate under high stress.
Similar or obsolete designations and trade names
- Plate specifications: AMS 4044 / 4045 / 4078, AMS QQ-A-250/12 / 24 (USA), AIR 9048.680 – .710 (France), 3.4364 (Germany), EN 2126, EN 2511 (Europe)
- Sheet specifications: AMS QQ-A-250/12 / 13 (clad), /24 /25 /26, AIR 9048.260 – .280 (France), 3.4364 / 3.4374 (Germany), L88 (UK)
- Common tempers: O, T6, T651, T73, T7351, T76, F, T7651, W51 (T651), L160 (UK bar)
- International names: AIZn6MgCu (ISO), ALZnMgCu1.5 (DIN), AIZn6MgCu1.5 (Switzerland), Zicral, Ergal, Fortal, Constructal
Main attributes
- Very high strength aluminium alloy (comparable to many steels)
- Good fatigue strength
- Increased strength at sub-zero temperatures
- Reduced strength at very high temperatures
- Less resistance to corrosion than many other aluminium alloys
- Some tempers offer improved stress-corrosion cracking resistance
- One of the highest strength to weight ratios of any aluminium alloy
- Generally speaking does not offer good weldability
- Heat treatable
- Can be highly polished
- Poor formability/workability
Attributes vary by temper
- T6 temper has the highest strength, but lowest resistance to stress-corrosion cracking
- T73 temper provides much improved stress-corrosion resistance, but decreased strength
- T76 temper provides improved exfoliation resistance and limited stress-corrosion resistance over T6 with some decrease in strength
- Further details about the treatment of tempers can be found in the ‘finishing & treatments’ tab below
Finishing & treatments
7075 can be heat treated, annealed, and aged. It is not ideal for anodising and may produce a yellowish tint when clear anodised.
Here is a summary of the available temper treatments:
- T6 – solution heat treated then artificially aged
- T651 – solution heat treated, stress relieved by stretching then artificially aged
- T73 – solution heat treated then artificially overaged to achieve best stress corrosion resistance
- T7351 – solution heat treated, stress relieved by stretching a controlled amount then artificially overaged to achieve best corrosion resistance
- T76 – solution heat treated then artificially overaged to achieve good exfoliation resistance
- T7651 – solution heat treated, stress relieved by stretching a controlled amount then artificially overaged to achieve good exfoliation corrosion resistance
See our Finishing Processes page for further information on services that we can facilitate.
7075 UK stock sizes
Stock sizes will vary depending on the supplier.
7075 plate is readily available in thickness ranging from 6mm - 150mm in most common metric and imperial sizes. Plate is subject to a cutting tolerance which can be up to +/- 8mm.
7075T6 bar is readily available in metric and imperial diameters ranging from 6mm - 260mm.
Please note we do not supply stock material, the information provided is purely for design and research purposes.
Technical properties
7075 aluminium physical properties
| Physical Property | Value |
| Density | 2.82 g/cm3 |
| Melting Point | 635°C |
| Thermal Expansion | 23.5 × 10−6/K |
| Modulus of Elasticity | 72 GPa |
| Thermal Conductivity | 134–160 W/m·K |
| Electrical Resistivity | 40% IACS |
The mechanical properties of aluminium 7075 depend greatly on the temper. Here are the values for 0 and T6 tempers.
| Mechanical Property | 0 Temper | T6 Temper |
| Proof Stress | 105–145 MPa | 435–505 MPa |
| Tensile Strength | 225–275 MPa | 510–570 MPa |
| Shear Strength | 150 MPa | 350 MPa |
| Elongation A5 | 9% | 5% |
| Hardness Vickers | 65 HV | 160 HV |
Typical 7075 chemical composition (weight %)
7075 Aluminium Alloy Composition by Weight (%) | Weight (%) | Manganese | Iron | Copper | Magnesium | Silicon | Zinc | Chromium | Titanium | Aluminium | Others |
| min. | 0.00 | 0.00 | 1.20 | 2.10 | 0.00 | 5.10 | 0.18 | 0.00 | Balance | 0.00 |
| max. | 0.30 | 0.50 | 2.00 | 2.90 | 0.40 | 6.10 | 0.28 | 0.20 | Balance | 0.15 |
Note for designers
Due to the relative higher cost of 7075 aluminium, it is generally only used where its superior strength is required.
Should the extra strength not be critical, aluminium 6082 which has less strength but superior corrosion resistance may be a better option.
Please feel free to get in touch with our engineering team who can advise on your project.
Contact us
