Aluminum 6061 t6 vs 7075: weight, strength and disadvantages comparison

Among the many grades of aluminum alloys, 6061-T6 and 7075 stand out as two of the most widely used and representative materials in modern engineering. Both share the general advantages of aluminum — lightweight, corrosion resistance, excellent formability, and a high strength-to-weight ratio — yet each possesses its own unique strengths and disadvantages

While 6061-T6 is known for its outstanding machinability, weldability, and balanced mechanical performance, 7075 offers exceptional hardness and tensile strength, often rivaling that of steel. These differences make them suitable for very different applications: one for general structural and industrial use, and the other for high-stress aerospace and defense components.

This article focuses on a detailed comparison between 6061-T6 and 7075 aluminum alloys in terms of weight, strength, and application suitability. By understanding the fundamental differences in composition and performance, engineers, designers, and buyers can make more informed decisions when selecting the right alloy for their specific projects — achieving the optimal balance between performance, cost, and reliability.

1. 6061 t6 vs 7075 composition 

6061 aluminum alloy (Al–Mg–Si Series)

6061 is primarily alloyed with magnesium (0.8–1.2%) and silicon (0.4–0.8%). These elements form the strengthening compound Mg₂Si, which significantly enhances mechanical strength after heat treatment.
Minor additions of copper (0.15–0.4%) improve strength without majorly affecting corrosion resistance, while chromium (0.04–0.35%) and manganese neutralize impurities and enhance corrosion resistance. Titanium (≤0.15%) refines the grain structure. With over 98% aluminum content, 6061 offers an excellent balance of strength, corrosion resistance, and machinability — a classic all-purpose alloy.

7075 aluminum alloy (Al–Zn–Mg–Cu Series)

7075's key alloying elements are zinc (5.1–6.1%), magnesium (2.1–2.9%), and copper (1.2–2.0%). These elements act synergistically to produce exceptional hardness and tensile strength.
Small additions of chromium (≤0.28%) reduce grain-boundary corrosion, while titanium and manganese further refine the microstructure. This alloy’s dense, precipitate-hardened structure makes 7075 one of the highest-strength aluminum alloys available.

2. 6061 t6 vs 7075 weight and density 

Theoretical density of 6061 is 2.70 g/cm³, slightly lower than 7075 at 2.80 g/cm³.
For equal volumes, 7075 parts are about 3–4% heavier. For instance, a 100 cm³ component weighs roughly 270 g in 6061 versus 280 g in 7075. While minor per part, this difference accumulates in weight-critical applications like aircraft or EVs, where every gram matters.

3. 6061 t6 vs 7075 strength 

6061-t6 aluminum

In T6 temper, 6061 exhibits a tensile strength of ≈310 MPa and yield strength of 240–276 MPa, with elongation of 8–12%. This provides good ductility and energy absorption under load. It is ideal for medium-duty structural parts such as car frames, window structures, and electronic housings.

7075-t6 aluminum

Known as the“powerhouse”among aluminum alloys, 7075-T6 offers tensile strength of 524–572 MPa and yield strength of 455–503 MPa, about double that of 6061. Its superior fatigue and impact resistance make it the material of choice for highly stressed aerospace and defense components — such as aircraft spars, landing gear, and armored vehicle structures — as well as high-end sports equipment like performance bike frames.

4. 6061 t6 vs 7075 disadvantages

6061 aluminum alloy

• Lower strength than 7075; unsuitable for extremely high-load components.

• Strength loss after welding, requiring post-weld heat treatment.

• Limited use in ultra-high-stress applications (e.g., bridge main beams, primary aerospace structures).

7075 aluminum alloy

• Difficult to machine due to high hardness, leading to faster tool wear.

• Poor weldability — prone to cracks and porosity during welding.

• Lower corrosion resistance, especially in marine or humid environments; requires surface treatments like anodizing or coating.

• Reduced formability, making it unsuitable for complex shapes.

5. Applications comparison

6. Material selection quick guidelines

If you're still unsure which alloy best fits your project, feel free to contact our team. Simply tell us about your intended application, and our experienced sales engineers will help you choose the most suitable material grade and cost-effective solution for your needs.