What Is the Difference Between 6082 and 7075 Aluminum?

Aluminum alloys are essential in modern manufacturing and construction industries due to their lightweight, strength, and corrosion resistance. Among the many available aluminum grades, 6082 and 7075 are two commonly used alloys, each offering distinct advantages. Whether you’re working in aerospace, marine, or structural applications, choosing the right alloy can make a significant difference in performance and cost. In this article, we will compare 6082 and 7075 aluminum in detail, covering their composition, mechanical properties, corrosion resistance, applications, and more.

1. Chemical Composition

The key difference between 6082 and 7075 aluminum starts with their chemical makeup, which influences all their mechanical and physical properties.

6082 Aluminum Composition (Approximate):

• Magnesium (Mg): 0.6–1.2%

• Silicon (Si): 0.7–1.3%

• Manganese (Mn): 0.4–1.0%

• Iron (Fe): 0.5% max

• Chromium (Cr): 0.25% max

• Zinc (Zn): 0.2% max

• Others: Trace amounts

7075 Aluminum Composition (Approximate):

• 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): 0.5% max

• Silicon (Si): 0.4% max

• Others: Trace amounts

7075 aluminum contains significantly more zinc and copper, which contributes to its superior strength but also makes it more prone to corrosion compared to 6082.

2. Mechanical Properties

Strength and durability are major differentiating factors between these two alloys.

6082 Aluminum Mechanical Properties:

• Ultimate Tensile Strength: 290–340 MPa

• Yield Strength: 240–310 MPa

• Elongation at Break: 10–18%

• Hardness (Brinell): 89 HB

7075 Aluminum Mechanical Properties:

• Ultimate Tensile Strength: 510–580 MPa

• Yield Strength: 430–480 MPa

• Elongation at Break: 5–11%

• Hardness (Brinell): 150 HB

Comparison:

• 7075 is significantly stronger and harder than 6082.

• 6082 offers better ductility and formability.

3. Corrosion Resistance

Corrosion resistance is crucial in applications exposed to moisture or harsh environments.

• 6082 Aluminum has excellent corrosion resistance, especially in marine and industrial settings, due to its lower copper content.

• 7075 Aluminum, while strong, has lower corrosion resistance due to its high zinc and copper content.

Conclusion:
For outdoor or marine applications, 6082 is generally the better choice in terms of long-term corrosion resistance.

4. Machinability and Weldability

6082 Aluminum:

• Good machinability

• Excellent weldability, especially with MIG and TIG methods

• Commonly used in structural welding and construction

7075 Aluminum:

• Good machinability (especially in T6 condition)

• Poor weldability due to high risk of cracking

• Typically used where welding is not required or minimal

If welding is a critical requirement, 6082 aluminum is far superior.

5. Heat Treatment and Temper

Both 6082 and 7075 aluminum can be heat-treated to improve their mechanical properties.

Common Tempers:

• 6082: T4 (solution heat-treated), T5, T6 (solution heat-treated and artificially aged)

• 7075: T6, T651, T73

7075-T6 is one of the strongest aluminum tempers available, while 6082-T6 provides a good balance of strength and corrosion resistance.

6. Weight and Density

Both alloys have similar densities:

• 6082 Aluminum: ~2.70 g/cm³

• 7075 Aluminum: ~2.81 g/cm³

Although 7075 is slightly heavier, the difference is minimal and usually not a decisive factor unless extreme weight saving is critical.

7. Cost and Availability

6082 Aluminum:

• More affordable

• Widely available in sheets, plates, bars, and tubes

• Common in general construction and engineering applications

7075 Aluminum:

• More expensive due to alloying elements and processing

• Typically found in aerospace-grade products and high-performance parts

If budget is a key concern, 6082 offers a more economical solution.

8. Applications

6082 Aluminum Applications:

• Structural components

• Marine frames and shipbuilding

• Bridges and cranes

• Transportation

• Architectural frames

7075 Aluminum Applications:

• Aerospace parts (wings, fuselage)

• High-performance bicycle frames

• Racing automotive parts

• Sporting equipment (archery bows, firearms)

• Aircraft fittings

sasaaluminum offers both 6082 and 7075 aluminum materials for a wide range of industrial and commercial uses.

9. Summary Table

Conclusion

When comparing 6082 vs 7075 aluminum, the best choice depends entirely on your specific application requirements. If your project requires high strength and low weight, and cost is not a barrier, 7075 aluminum is the superior option. On the other hand, if you need good corrosion resistance, weldability, and affordability, 6082 aluminum is the more practical solution.

sasaaluminum supplies a complete range of aluminum products, including both 6082 and 7075 alloys, in multiple forms such as plates, bars, and tubes. Whether you are in aerospace, construction, or industrial fabrication, we can help you find the right alloy for your needs.