Aluminium 7075-T6
Aerospace high-strength. UTS 572 MPa — the benchmark for machined aircraft structural parts.
7075-T6 is a Zn-Mg-Cu-Cr precipitation-hardened alloy with the highest strength of standard Al alloys (UTS ~572 MPa, YS ~503 MPa). It dominates aerospace structural machining: wing skins, spar caps, fuselage bulkheads, landing-gear components. Susceptible to stress corrosion cracking (SCC) — specify T7351 for SCC-critical service. Not weldable.
Equivalent Designations
| Standard | Designation |
|---|---|
| UNS | A97075 |
| Werkstoff Nr. | 3.4365 |
| EN | EN AW-7075 |
Standards
ASTM B211, AMS 4122, 4123, 4124, 4186 — rolled/cold-finishedASTM B221, AMS 4154, 4166, 4167 — extrudedAMS-QQ-A-225/9, AMS-QQ-A-200/11 — military / aerospace
Chemical Composition (% by mass)
| Si | 0.40 max |
| Fe | 0.50 max |
| Cu | 1.2–2.0 |
| Mn | 0.30 max |
| Mg | 2.1–2.9 |
| Cr | 0.18–0.28 |
| Zn | 5.1–6.1 |
| Ti | 0.20 max |
| Al | Remainder |
| Others (each / total) | 0.05 / 0.15 |
Mechanical Properties
| Ultimate Tensile Strength (T6, T651) | 572 MPa (83 ksi) |
| Yield Strength (T6, T651) | 503 MPa (73 ksi) |
| Elongation | 11 % |
| Brinell Hardness | 150 HB |
Physical Properties
| Density | 2.81 g/cm³ |
| Melting Point | 475–635 °C |
| Modulus of Elasticity | 71.7 GPa |
| Thermal Conductivity | 130 W/m·K |
Available Forms & Sizes
| Form | Size Range | Notes |
|---|---|---|
| Round Bar (Cold drawn & ground) | Ø10 to Ø75 mm | Tolerance h8/h9/h10/h11 |
| Round Bar (Peeled & polished) | Ø40 to Ø150 mm | Tolerance h11 |
| Round Bar (Peeled & ground) | Ø20 to Ø50 mm | Tolerance h9/h10/h11 |
| Round Bar (Cold drawn & polish) | Ø3 to Ø75 mm | Tolerance h8/h9/h10/h11 |
| Plate / Sheet | 6 mm to 200 mm thick | T7351 preferred for >75 mm |
Tempers Available
Use Cases
Aerospace structural
Wing skins, spar caps, fuselage bulkheads, landing-gear components — the benchmark for high strength-to-weight in machined aerospace parts.
High-stress fittings
UAV airframes, weapon mount brackets, gimbal arms where weight matters.
Mould tooling for composite layup
High stiffness and dimensional stability after machining.
Sporting goods
Bicycle frames, archery, recoil-loaded firearm components.
Design Notes
- DO NOT WELD 7075 — it cracks in the HAZ. Bond or fasten mechanically. If welded structure required, redesign or switch to 7050-T7451 with peen-stress relief.
- SCC management: for marine or chloride-rich service, specify T7351 (overaged, better SCC resistance) instead of T651.
- For plate thickness > 75 mm, switch to 7050-T7451 (better thick-section properties and SCC resistance).
Indian Sourcing
Aerospace tempers (T651, T7351) typically imported (Constellium, Kaiser, Aleris). Domestic sources offer commercial T6 in standard sizes; aerospace heat-numbered traceability requires import lead times of 2–4 weeks.