6061 Aluminum: Common Temper Grades &Material Properties

6061 aluminum is a versatile and widely used alloy, known for its excellent combination of strength, corrosion resistance, and weldability.

Widely recognized and used by engineers, machinists, fabricators, and welders for a variety of applications.

6061 aluminum, along with its counterpart 6063, is a go-to choice for structural aluminum. It finds applications in diverse fields, including aerospace components, marine fittings, and heavy-duty construction equipment.

Compared to 6063, 6061 boasts significantly higher tensile and yield strength, making it the preferred option for demanding structural requirements.

Although not the strongest aluminum alloy available, 6061 stands out for its balanced properties.

Its combination of excellent corrosion resistance, good machinability, and impressive tensile strength ensures widespread use across industries.

Additionally, 6061 aluminum is highly adaptable, easy to process, and forgiving during fabrication.

It can be cut, welded, and shaped with relative ease, delivering consistent and dependable results even in complex manufacturing processes.

Common Temper Grades of 6061 Aluminum & Material Properties

6061 aluminum is a versatile and widely used alloy, known for its excellent combination of strength, corrosion resistance, and weldability.

It is available in several temper grades, each designed to meet specific mechanical property requirements. Here’s a comprehensive overview:

Summary Table of Material Properties

1. 6061-O (Annealed)

• Density (g/cm³): 2.70
• Tensile Strength (MPa): 120-150
• Yield Strength (MPa): 55-70
• Modulus of Elasticity (GPa): 68.3
• Brinell Hardness (500g, 10mm ball): 35-45
• Elongation at Break (%): 25-35
• Shear Modulus (GPa): 26.0
• Shear Strength (MPa): 70-90
• Fatigue Strength (MPa): 70-90
• Thermal Expansion Coefficient (μm/m·°C): 23.6
• Solidus Temperature (°C): 577
• Liquidus Temperature (°C): 635
• Annealing Temperature (°C): 343-454
• Solution Treatment Temperature (°C): Not applicable
• Thermal Conductivity (W/m·K): 151
• Specific Heat Capacity (J/kg·K): 896

Applications: 6061-O is often used in deep-drawing operations and other forming processes where maximum formability and low strength are required.

Its high elongation makes it ideal for applications that require significant deformation without breaking.

2. 6061-T4 (Solution Heat-Treated and Naturally Aged)

• Density (g/cm³): 2.70
• Tensile Strength (MPa): 240-290
• Yield Strength (MPa): 130-180
• Modulus of Elasticity (GPa): 68.3
• Brinell Hardness (500g, 10mm ball): 70-90
• Elongation at Break (%): 12-15
• Shear Modulus (GPa): 26.0
• Shear Strength (MPa): 140-160
• Fatigue Strength (MPa): 140-160
• Thermal Expansion Coefficient (μm/m·°C): 23.6
• Solidus Temperature (°C): 577
• Liquidus Temperature (°C): 635
• Annealing Temperature (°C): 343-454
• Solution Treatment Temperature (°C): 445-465
• Thermal Conductivity (W/m·K): 151
• Specific Heat Capacity (J/kg·K): 896

Applications: 6061-T4 is commonly used in applications where moderate strength and good formability are required.

It is often found in extrusions, tubing, and general structural components. The natural aging process helps achieve a balanced set of mechanical properties.

3. 6061-T5 (Solution Heat-Treated and Cooled to Stabilize Microstructure)

• Density (g/cm³): 2.70
• Tensile Strength (MPa): 240-270
• Yield Strength (MPa): 160-210
• Modulus of Elasticity (GPa): 68.3
• Brinell Hardness (500g, 10mm ball): 70-90
• Elongation at Break (%): 10-12
• Shear Modulus (GPa): 26.0
• Shear Strength (MPa): 140-160
• Fatigue Strength (MPa): 140-160
• Thermal Expansion Coefficient (μm/m·°C): 23.6
• Solidus Temperature (°C): 577
• Liquidus Temperature (°C): 635
• Annealing Temperature (°C): 343-454
• Solution Treatment Temperature (°C): 445-465
• Thermal Conductivity (W/m·K): 151
• Specific Heat Capacity (J/kg·K): 896

Applications: 6061-T5 is less common but useful in applications where a balance of strength and formability is needed, and natural aging is not desired.

It is often used in extruded sections and structural components.

4. 6061-T6 (Solution Heat-Treated and Artificially Aged)

• Density (g/cm³): 2.70
• Tensile Strength (MPa): 276-310
• Yield Strength (MPa): 230-270
• Modulus of Elasticity (GPa): 68.3
• Brinell Hardness (500g, 10mm ball): 95-125
• Elongation at Break (%): 8-10
• Shear Modulus (GPa): 26.0
• Shear Strength (MPa): 160-200
• Fatigue Strength (MPa): 160-200
• Thermal Expansion Coefficient (μm/m·°C): 23.6
• Solidus Temperature (°C): 577
• Liquidus Temperature (°C): 635
• Annealing Temperature (°C): 343-454
• Solution Treatment Temperature (°C): 445-465
• Thermal Conductivity (W/m·K): 151
• Specific Heat Capacity (J/kg·K): 896

Applications: 6061-T6 is the most common temper grade for 6061 aluminum.

It offers a good balance of strength and formability, making it suitable for a wide range of applications, including bicycle frames, aircraft parts, and architectural structures.

The artificial aging process enhances its mechanical properties.

5. 6061-T651 (Solution Heat-Treated, Stress-Relieved, and Artificially Aged)

• Density (g/cm³): 2.70
• Tensile Strength (MPa): 276-310
• Yield Strength (MPa): 230-270
• Modulus of Elasticity (GPa): 68.3
• Brinell Hardness (500g, 10mm ball): 95-125
• Elongation at Break (%): 8-10
• Shear Modulus (GPa): 26.0
• Shear Strength (MPa): 160-200
• Fatigue Strength (MPa): 160-200
• Thermal Expansion Coefficient (μm/m·°C): 23.6
• Solidus Temperature (°C): 577
• Liquidus Temperature (°C): 635
• Annealing Temperature (°C): 343-454
• Solution Treatment Temperature (°C): 445-465
• Thermal Conductivity (W/m·K): 151
• Specific Heat Capacity (J/kg·K): 896

Applications: 6061-T651 is similar to 6061-T6 but includes an additional stress-relieving process.

This process reduces internal stresses and improves machinability, making it ideal for precision machining applications, such as aircraft components and high-tolerance parts.

Conclusion

6061 aluminum is a highly versatile material, with each temper grade offering unique properties to suit specific applications.

The most commonly used temperature is 6061-T6, which provides a good balance of strength and formability.

However, other tempers like 6061-T4, 6061-T5, and 6061-T651 offer different advantages in terms of formability, machinability, and cost-effectiveness.

Understanding these properties can help in selecting the appropriate temper grade for your specific needs.

If you have any more specific questions or needs, feel free to contact us!