6061 vs. 6063:
Which Aluminum Alloy You Should Use

Aluminum alloys are a crucial component in many industries, including construction, automotive, aerospace, medical, furniture and more. These alloys are known for their lightweight, high strength, corrosion resistance, and excellent thermal conductivity. Among the wide range of aluminum alloys available, 6061 and 6063 are frequently utilized and compared due to their similarities in composition and applications.

Aluminum alloys are widely used in various industries due to their exceptional properties and versatility. Two popular aluminum alloys that often come into comparison are 6061 and 6063. In this article, we will delve into the key differences between these two alloys and determine which one reigns supreme.

Aluminum alloys are formed by combining aluminum with various elements such as copper, magnesium, manganese, or silicon. These alloying elements enhance the properties of aluminum, making it more suitable for specific applications. The addition of alloying elements alters the characteristics of aluminum, including its strength, hardness, machinability, and corrosion resistance.

Properties of Alloys

6061 Alloys

6061 aluminum alloy is a precipitation-hardened alloy, primarily composed of aluminum, magnesium, and silicon. It offers excellent strength, good corrosion resistance, and high weldability. This alloy is known for its exceptional structural integrity and is commonly used in applications that require high strength and durability.

6063 Alloys

6063 aluminum alloy is an extrusion alloy with a high silicon content, which gives it good formability and surface finish. It has slightly lower strength compared to 6061 but offers excellent corrosion resistance and is highly suitable for intricate shapes and designs. This alloy is often chosen for applications where aesthetics and appearance are important.

Comparison of 6061 and 6063 Alloys

When comparing 6061 and 6063 aluminum alloys, several factors come into play. Let’s examine the key differences between these two alloys in terms of strength and hardness, machinability and weldability, corrosion resistance, surface finish, applications, and price and availability.

  • Strength and Hardness

6061 aluminum alloy has higher strength and hardness compared to 6063 alloy. This makes 6061 more suitable for applications where structural integrity and load-bearing capacity are crucial.

  • Machinability and Weldability

Both alloys exhibit good machinability, but 6061 is generally easier to machine due to its higher strength. When it comes to weldability, 6061 and 6063 alloys have similar characteristics, making them suitable for welding processes.

  • Corrosion Resistance

6061 and 6063 alloys offer excellent corrosion resistance. However, 6063 has better resistance to corrosion in saltwater environments, making it a preferred choice for marine applications.

  • Surface Finish

6063 alloy is well-regarded for its superior surface finish, making it ideal for applications where aesthetics are a priority. In contrast, 6061 alloy may require additional surface treatments to achieve a similar level of finish.

  • Applications of 6061 Alloy

6061 aluminum alloy finds extensive use in various industries. Its strength and durability make it suitable for structural components, such as aircraft parts, bicycle frames, automotive parts, and machinery components. Additionally, it is commonly utilized in the construction of buildings, bridges, and marine structures.

  • Applications of 6063 Alloy

6063 aluminum alloy is widely employed in architectural and decorative applications due to its excellent formability and surface finish. It is often used in window frames, door frames, curtain walls, and other intricate extruded shapes.

  • Price and Availability

In terms of price, 6061 and 6063 alloys are generally comparable with 6061 being slightly higher. However, availability may vary depending on the region and specific applications. It is advisable to consult with suppliers or experts to determine the availability and cost of these alloys in your area.


Both 6061 and 6063 aluminum alloys have their own unique properties and applications. The choice between the two depends on the specific requirements of the project or application. If high strength and structural integrity are crucial, 6061 is an excellent choice. On the other hand, if aesthetics and surface finish are a priority, 6063 offers superior results. It is essential to consider the intended use, environment, and budget when selecting the most suitable alloy.