When it comes to high-performance aluminum alloys, 7075 and 7005 are two of the most widely used grades in structural engineering, aerospace, cycling, automotive, and sporting goods. Both belong to the 7000 series, which is known for its high strength and excellent mechanical properties. However, while they may seem similar at first glance, there are distinct differences between 7075 and 7005 aluminum that make each better suited for specific applications.
In this article, we’ll explore the chemical composition, mechanical properties, corrosion resistance, weldability, cost, and applications of 7075 vs 7005 aluminum. Whether you are a procurement manager, product engineer, or metal fabricator, this guide will help you make the right material choice for your next project.
Let’s dive into the key differences between 7075 aluminum and 7005 aluminum.
1. Chemical Composition
The primary alloying element in both 7075 and 7005 is zinc (Zn). However, the supporting alloying elements differ, which significantly affects their properties.
| Element | 7075 Aluminum (%) | 7005 Aluminum (%) |
|---|---|---|
| Zinc (Zn) | 5.1 – 6.1 | 4.0 – 5.0 |
| Magnesium (Mg) | 2.1 – 2.9 | 1.0 – 1.8 |
| Copper (Cu) | 1.2 – 2.0 | 0.1 max |
| Chromium (Cr) | 0.18 – 0.28 | — |
| Manganese (Mn) | — | 0.2 – 0.7 |
| Silicon (Si) | 0.4 max | 0.35 max |
| Iron (Fe) | 0.5 max | 0.35 max |
Key difference:
7075 contains more copper and magnesium, giving it higher strength but lower corrosion resistance. 7005 is copper-free, which makes it more corrosion-resistant and easier to weld.
2. Mechanical Properties
One of the main reasons engineers choose from the 7000 series is the strength. Here’s how 7075 and 7005 compare:
| Property | 7075-T6 | 7005-T6 |
|---|---|---|
| Ultimate Tensile Strength | ~570 MPa | ~390 MPa |
| Yield Strength | ~500 MPa | ~350 MPa |
| Elongation | ~10% | ~12% |
| Hardness (Brinell) | ~150 | ~85 |
| Density | 2.81 g/cm³ | 2.78 g/cm³ |
Key takeaway:
7075 aluminum is significantly stronger and harder than 7005, making it ideal for aerospace and defense applications. On the other hand, 7005 offers better flexibility and ductility, which can be advantageous in structural applications like bicycle frames.
3. Corrosion Resistance
7075 aluminum is known for having lower corrosion resistance, especially in saltwater or humid environments. The presence of copper contributes to its strength but makes it more susceptible to corrosion.
7005 aluminum, being copper-free, has much better resistance to corrosion, making it a better choice for outdoor and marine environments.
For environments where corrosion resistance is a top priority, 7005 aluminum is generally preferred.
4. Weldability
One of the biggest functional differences between 7075 and 7005 lies in their weldability.
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7075 aluminum is not weldable by conventional means due to its high copper content. Welding can create cracks or reduce mechanical strength.
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7005 aluminum is highly weldable, especially using TIG or MIG welding methods. After welding, it can also regain strength through natural or artificial aging.
If welding is required, 7005 is the clear choice.
5. Machinability and Formability
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7075 aluminum has excellent machinability but poor formability. It tends to crack or tear under deep drawing or complex bending.
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7005 aluminum offers good formability, especially in the T5 or T6 temper, and is more forgiving in forming operations.
For CNC machining or tight tolerances, 7075 is better. For forming or bending applications, 7005 is preferred.
6. Heat Treatment and Aging
Both alloys can be heat-treated to improve strength:
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7075 is commonly used in T6 temper (solution heat-treated and artificially aged), offering maximum strength.
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7005 can also be heat-treated (T5 and T6), but even in its peak aged condition, its strength is lower than 7075.
However, 7005 can naturally age after welding to recover strength without needing high-temperature treatment.
7. Price and Availability
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7075 aluminum is more expensive due to its high-strength formulation and aerospace applications.
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7005 aluminum is more cost-effective and readily available for commercial and recreational use.
If budget is a concern and ultra-high strength is not needed, 7005 offers a more economical solution.
8. Common Applications
| Application Type | 7075 Aluminum | 7005 Aluminum |
|---|---|---|
| Aerospace components | Aircraft wing spars, fuselages | Support brackets |
| Sporting goods | Climbing gear, compound bows | Bicycle frames, tent poles |
| Automotive parts | Racing components, suspension arms | Roof racks, structural panels |
| Military/Defense | Firearms, armor plates | Lightweight shelters, racks |
| Marine | — (not recommended) | Boat masts, marine frames |
sasaaluminum provides both 7075 and 7005 aluminum products in plates, bars, tubes, and custom shapes, ensuring the right alloy for your specific application.
9. Summary: 7075 vs 7005 Aluminum
| Feature | 7075 Aluminum | 7005 Aluminum |
|---|---|---|
| Strength | Higher | Moderate |
| Corrosion Resistance | Lower | Higher |
| Weldability | Poor | Excellent |
| Machinability | Excellent | Good |
| Formability | Poor | Better |
| Price | Higher | Lower |
| Heat Treatable | Yes | Yes |
| Common Use | Aerospace, military | Cycling, sports, outdoor |
Which One Should You Choose?
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Choose 7075 aluminum if you need maximum strength, such as for aerospace, high-performance racing, or defense parts.
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Choose 7005 aluminum if you need good corrosion resistance, weldability, and moderate strength at a lower cost, such as for bicycle frames, marine structures, or outdoor equipment.
Consult with a trusted supplier like sasaaluminum to evaluate your project requirements and select the right aluminum alloy.
Final Thoughts
Understanding the difference between 7075 and 7005 aluminum is essential when choosing the right material for your engineering or manufacturing needs. Both alloys are powerful in their own way. 7075 offers unmatched strength, while 7005 brings affordability, weldability, and durability in corrosive environments.
At sasaaluminum, we supply top-quality aluminum alloys including 7075 and 7005 in various tempers and product forms. Contact our technical team to get expert advice, custom quotes, or to place your order with full confidence.
Post time: Aug-07-2025