The 7075 aluminum alloy is one of the highest-strength aluminum alloys available, earning its reputation as the backbone of aerospace manufacturing. Known for its exceptional strength-to-weight ratio, 7075 aluminum is the material of choice for aircraft structures, military equipment, and high-performance sporting goods. This comprehensive guide covers everything engineers, procurement specialists, and manufacturers need to know about 7075 aluminum — from its chemical composition and mechanical properties to real-world applications and sourcing considerations.
What Is 7075 Aluminum Alloy?
7075 aluminum is a zinc-aluminum alloy belonging to the 7xxx series, developed originally by Sumitomo Metal Industries in Japan during the 1940s and later adopted extensively in the aerospace industry. Its primary alloying element is zinc (5.1–6.1%), supplemented by magnesium (2.1–2.9%) and copper (1.2–2.0%), which together create a precipitation-hardened alloy with tensile strengths exceeding 570 MPa in the T6 temper.
Often referred to as “aircraft aluminum” or “aerospace grade aluminum,” 7075 outperforms many steels on a strength-to-weight basis while maintaining approximately one-third the density of steel. For a broader comparison across aluminum families, see our guide on 6061 vs 7075 Aluminum and our 7000 Series Aluminum product page.
Chemical Composition of 7075 Aluminum
| Element | Composition Range |
|---|---|
| Zinc (Zn) | 5.1 – 6.1% |
| Magnesium (Mg) | 2.1 – 2.9% |
| Copper (Cu) | 1.2 – 2.0% |
| Chromium (Cr) | 0.18 – 0.28% |
| Iron (Fe) | ≤ 0.50% |
| Silicon (Si) | ≤ 0.40% |
| Manganese (Mn) | ≤ 0.30% |
| Titanium (Ti) | ≤ 0.20% |
| Other (each) | ≤ 0.05% |
| Aluminum (Al) | Balance |
The high zinc and magnesium content creates the MgZn2 precipitate phase (η phase), which is the primary strengthening mechanism in 7075 aluminum. Understanding temper designations is crucial — our article on Decoding Aluminum Temper Designations explains how heat treatment dramatically affects properties.
Mechanical Properties of 7075 Aluminum by Temper
7075-T6 (Peak Aged)
| Property | 7075-T6 |
|---|---|
| Ultimate Tensile Strength | 510 – 572 MPa (74 – 83 ksi) |
| Yield Strength | 434 – 503 MPa (63 – 73 ksi) |
| Elongation at Break | 7 – 11% |
| Brinell Hardness | 150 – 160 HB |
| Fatigue Strength | 159 MPa (23 ksi) |
| Elastic Modulus | 71.7 GPa (10,400 ksi) |
| Density | 2.81 g/cm³ (0.1016 lb/in³) |
7075-T73 (Overaged for SCC Resistance)
The T73 temper sacrifices approximately 15% of peak tensile strength to dramatically improve stress corrosion cracking (SCC) resistance. This is critical for structural aerospace components exposed to harsh environments. Typical properties include tensile strength of 455–503 MPa and yield strength of 385–455 MPa.
7075-T76 (Overaged, Balanced)
T76 offers a compromise between T6 strength and T73 corrosion resistance, often specified for components requiring both high strength and improved SCC performance.
Key Advantages of 7075 Aluminum
- Exceptional strength: One of the strongest commercial aluminum alloys, rivaling many steels
- High strength-to-weight ratio: Ideal for weight-critical applications in aerospace and defense
- Good fatigue resistance: Suitable for cyclically loaded structural components
- Machinability: Excellent machinability in the T6 temper, producing clean chips and fine finishes
- Availability: Widely stocked in sheet, plate, bar, and tube forms from suppliers like HXM Aluminum
Limitations and Considerations
- Weldability: 7075 is generally considered non-weldable by conventional methods due to hot cracking and loss of strength in the heat-affected zone; mechanical fastening or friction stir welding is preferred
- Corrosion resistance: Inferior to 5xxx and 6xxx series alloys; requires protective coatings or anodizing for outdoor applications
- Stress corrosion cracking: Susceptible in T6 temper; T73 or T76 overaged tempers recommended for critical structural applications
- Cost: More expensive than 6061 or 5052 due to alloying content and processing requirements
- Formability: Limited formability in T6 temper; not suitable for complex forming operations
Primary Applications of 7075 Aluminum
Aerospace & Aviation
7075 aluminum is the dominant alloy in aircraft construction, used for fuselage frames, wing spars, wing skins, bulkheads, and landing gear components. Commercial aircraft from Boeing and Airbus extensively use 7075-T6 and 7075-T73. For sourcing, see our guide on Top Aircraft Aluminum Suppliers in China.
Military & Defense
Military applications include armored vehicle components, missile parts, firearm receivers, and submarine structures. The alloy’s high strength and lightweight nature are essential for defense applications where performance cannot be compromised.
Sporting Goods & Recreation
High-end bicycle frames, rock climbing carabiners, lacrosse sticks, and premium baseball bats use 7075 aluminum for its combination of strength and low weight.
Automotive Performance
In motorsport and high-performance automotive applications, 7075 is used for drive shafts, differential housings, and suspension components. For general automotive aluminum, aluminum bar stock and aluminum tubing from HXM offer versatile solutions.
Mold & Tooling
7075 aluminum plates are used for injection mold tooling and blow mold applications, offering faster cycle times and improved thermal conductivity compared to steel molds.
7075 vs Other Aluminum Alloys
7075 vs 6061
6061 is the most versatile aluminum alloy, offering excellent corrosion resistance, weldability, and formability at a lower cost. However, 7075 is nearly twice as strong. For a detailed comparison, read our 6061 vs 7075 Aluminum guide. Choose 6061 when weldability and corrosion resistance are priorities; choose 7075 when maximum strength is required.
7075 vs 2024
2024 aluminum offers better fatigue resistance and damage tolerance than 7075, making it preferred for aircraft skin and lower wing structures. 7075 provides higher static strength and is used for upper wing surfaces and fuselage frames. See our 2024 vs 7075 Aluminum comparison for details.
7075 vs 5052
These alloys serve completely different purposes. 5052 aluminum excels in corrosion resistance and formability for marine and sheet metal applications, while 7075 provides unmatched strength for structural uses. They are rarely interchangeable.
7075 Aluminum Product Forms Available from HXM
HXM Aluminum supplies 7075 aluminum in various forms to meet diverse manufacturing requirements:
- 7075 Aluminum Sheet & Plate: Available from 0.3mm to 200mm thickness, T6 and T73 tempers
- 7075 Aluminum Bar & Rod: Round, square, hex, and flat bar in various diameters and dimensions
- 7075 Aluminum Tube: Seamless and drawn tubes for structural applications
- 7075 Aluminum Forgings: Custom forged shapes per customer specifications
All products undergo rigorous quality testing including ultrasonic inspection, tensile testing, and chemical analysis. Custom dimensions and tempers are available upon request.
How to Source 7075 Aluminum: Buyer’s Checklist
- Specify the correct temper: T6 for maximum strength, T73 for SCC-critical applications, T76 for balanced performance
- Request mill test certificates (MTC): Verify chemical composition and mechanical properties meet AMS, ASTM, or EN standards
- Check dimensional tolerances: Aerospace applications require tight tolerances per AMS 4044 (sheet) or AMS 4126 (bar)
- Verify supplier qualifications: Look for AS9100 or ISO 9001 certified suppliers like HXM Aluminum
- Consider lead times: 7075 in uncommon sizes may require mill production runs of 4–8 weeks
- Evaluate surface finish requirements: Specify anodizing, painting, or bare finish as needed for corrosion protection
Frequently Asked Questions About 7075 Aluminum
Can 7075 aluminum be welded?
Conventional arc welding (MIG/TIG) is not recommended for 7075 due to hot cracking and severe strength loss in the heat-affected zone. Friction stir welding (FSW) can be used successfully. Mechanical fastening (rivets, bolts) is the standard joining method in aerospace.
Is 7075 aluminum corrosion resistant?
7075 has relatively poor corrosion resistance compared to 5xxx and 6xxx series alloys. It is susceptible to stress corrosion cracking in the T6 temper and exfoliation corrosion. Protective measures include anodizing, painting, or using the T73/T76 temper for improved resistance.
What is the difference between 7075-T6 and 7075-T73?
T6 is the peak-aged temper offering maximum tensile strength (~572 MPa) but with higher SCC susceptibility. T73 is an overaged temper with approximately 15% lower strength but dramatically improved stress corrosion cracking resistance, making it the preferred choice for critical structural aerospace components.
Why is 7075 called “aircraft aluminum”?
7075 earned the “aircraft aluminum” designation because it has been the primary structural alloy in aircraft manufacturing since World War II. Its combination of high strength, lightweight, and proven performance in aviation makes it the most widely used aluminum alloy in the aerospace industry.
Conclusion
7075 aluminum remains the gold standard for high-strength, lightweight structural applications across aerospace, defense, motorsport, and high-performance industries. Its exceptional mechanical properties — particularly in the T6 temper — make it irreplaceable for applications where strength-to-weight ratio is paramount. While it has limitations in weldability and corrosion resistance, proper temper selection (T73/T76) and protective treatments can mitigate these concerns.
For sourcing 7075 aluminum sheet, plate, bar, and tube with certified quality and competitive pricing, contact HXM Aluminum today. As a direct manufacturer with comprehensive quality testing capabilities and customization services, HXM delivers aerospace-grade 7075 aluminum to customers worldwide.
Related reading: 6061 vs 7075 Aluminum | 2024 vs 7075 Aluminum | 2000 vs 7000 Aluminum Alloy | Aluminum Temper Designations Explained | Density of Aluminum Alloys
