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6061 vs 6063: Delving into the World of Aluminum Alloys

Author: Yaozu Deng
Published on: 2023-08-11

The ever-evolving world of engineering and manufacturing materials is extensive, with every element bringing its unique attributes and applications. But few can argue against the versatility and popularity of aluminum, specifically the 6061 and 6063 alloys. Touted for their excellent mechanical properties, these alloys have found their way into a wide variety of applications, from construction to automobile manufacturing and beyond. Yet, understanding these two powerhouses of the aluminum world goes beyond merely recognizing their existence.

This article aims to shed light on the composition, strength, and unique characteristics of these two alloys, enabling you to make an informed decision about their application in your projects. Dive into the world of 6061 and 6063 and discover which one aligns with your needs.


6061 Aluminum: An Overview

Aluminum 6061 is one of the most commonly used aluminum alloys and for a good reason. It offers an excellent balance of mechanical properties and corrosion resistance, making it a preferred choice in many applications.

6061 Aluminum stock

6061 is a member of the 6000 series of aluminum, which means it’s alloyed with silicon and magnesium. Specifically, it contains about 0.8-1.2% silicon and 0.15-0.4% copper, with the balance being aluminum and minor quantities of other elements. This combination results in an alloy that’s highly workable and can be easily welded, making it incredibly versatile.

The mechanical properties of 6061 aluminum are impressive. It possesses a yield strength of about 40,000 psi and a tensile strength of around 45,000 psi. Furthermore, it has an excellent strength-to-weight ratio, which makes it suitable for applications that require strength but need to minimize weight.

As for corrosion resistance, 6061 aluminum performs exceptionally well, particularly when it’s anodized or covered with a protective coating. This characteristic makes it a favorite in industries like marine applications or outdoor equipment, where resistance to the elements is crucial.

One notable feature of 6061 aluminum is its heat-treatability. Heat treating 6061 can significantly improve its mechanical properties, particularly its hardness. This process involves heating the alloy to a specific temperature, holding it at that temperature for a certain time, and then cooling it rapidly. Heat-treated 6061-T6 is one of the most common forms of this alloy and boasts even higher strength levels.

Table 1: Properties of 6061 aluminum

Property Value
Composition (%) 0.8-1.2% Si, 0.15-0.4% Cu, Balance Al
Yield Strength (psi) ~40,000
Tensile Strength (psi) ~45,000
Heat Treatable Yes
Corrosion Resistance Excellent
Workability High


6063 Aluminum: Unveiling the Details

6063 Aluminum part

Also a part of the 6000 series, aluminum 6063 shares some similarities with 6061. However, it has unique attributes that set it apart and make it more suitable for certain applications.

The composition of 6063 aluminum is slightly different from 6061. It contains about 0.2-0.6% silicon and 0.45-0.9% magnesium. Also, 6063 aluminum has a small amount of iron, copper, and chromium in its composition. These elements give it excellent formability, making it the best choice for applications that require complex shapes and intricate designs.

When it comes to mechanical properties, 6063 aluminum offers lower strength than 6061. It has a yield strength of approximately 21,000 psi and a tensile strength of around 27,000 psi. Despite the lower strength, it’s a favorable choice for applications where formability and aesthetics take precedence over high strength.

6063 aluminum has excellent corrosion resistance, similar to 6061. It’s also heat-treatable and can be anodized to improve its corrosion resistance further, as well as its aesthetic appeal. The common form is the heat-treated 6063-T5, which exhibits a high degree of resistance to corrosion and surface wear.

A look at the properties of 6063 aluminum reveals its suitability for applications where strength is secondary to the surface finish.

Table 2: Various properties of 6063 aluminum

Property Value
Composition (%) 0.2-0.6% Si, 0.45-0.9% Mg, Balance Al
Yield Strength (psi) ~21,000
Tensile Strength (psi) ~27,000
Heat Treatable Yes
Corrosion Resistance Excellent
Formability High


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Composition: 6063 vs 6061 Aluminum

When comparing 6063 and 6061 aluminum, it’s crucial to understand their compositions to comprehend their properties and potential applications better. Although they belong to the same series, slight variations in their alloying elements lead to significant differences in their mechanical properties and uses.

6061 aluminum comprises more silicon and copper than 6063, contributing to its higher strength and hardness. This makes 6061 aluminum better suited for applications that require more strength, like in construction or automotive parts.

On the other hand, 6063 aluminum, with its higher magnesium content and lower silicon, leans more towards formability and workability. This composition favors applications that require intricate designs and superior surface finishes, like window frames and trim.

Table 3: Composition comparison

Composition elements 6061 Aluminum 6063 Aluminum
Silicon (%) 0.8-1.2 0.2-0.6
Magnesium (%) 0.15-0.4 0.45-0.9
Copper (%) Minor Minor
Iron (%) Minor Minor
Chromium (%) Minor Minor
Strength Higher Lower
Formability Lower Higher
Corrosion Resistance Excellent Excellent
Heat Treatable Yes Yes

It’s essential to note that these differences, while seemingly minor, can significantly impact the alloy’s performance in a specific application. Understanding these differences is paramount for engineers and manufacturers when choosing the right aluminum alloy for their projects.


Strength and Hardness: 6063 vs 6061 Aluminum

A significant determinant of how suitable an aluminum alloy is for a specific application is its mechanical properties, particularly strength and hardness. Strength is defined as the maximum stress that a material can withstand while being stretched or pulled before necking or breaking, whereas hardness is a measure of a material’s resistance to localized deformation like denting or scratching.

6061 aluminum, owing to its higher silicon and copper content, has greater strength and hardness compared to 6063. It has a tensile strength of about 45,000 psi and a yield strength of around 40,000 psi. This high strength-to-weight ratio makes 6061 an excellent choice for applications where material strength is a critical factor such as in the construction of aircraft and yacht components, bicycle frames, and all-terrain vehicle (ATV) parts.

6063 aluminum, although less strong than its 6061 counterpart, is still widely employed in applications where its excellent formability and aesthetic properties are prized over its strength. It has a tensile strength of about 27,000 psi and a yield strength of approximately 21,000 psi. These properties make it suitable for intricate molding applications such as decorative trim, architectural elements, and window frames.

Table 4: Properties of two aluminum grades

Property 6061 Aluminum 6063 Aluminum
Tensile Strength (psi) ~45,000 ~27,000
Yield Strength (psi) ~40,000 ~21,000
Hardness (Brinell) 95 73
Strength-to-weight Ratio High Moderate


Workability: Molding the Perfect Component

Workability is another critical aspect to consider when comparing 6061 and 6063 aluminum. This term refers to how easily a material can be manipulated into different shapes without breaking – a particularly crucial factor in industries such as architecture and design.

6063 aluminum is often chosen for applications that require intricate molding and shaping due to its excellent workability. The alloy’s low melting point, along with its ability to resist corrosion even when deformed, makes it a suitable choice for creating complex shapes and designs. It’s regularly used in extrusion processes, where it can be pushed through dies to create a wide array of shapes.

Conversely, the higher strength and hardness of 6061 aluminum make it less workable than 6063. However, it is still very capable of being extruded and formed, albeit requiring a bit more force. Its resistance to corrosion and weldability make it a good choice for structural applications where high strength is needed.

Table 5: Formability of 6061 and 6063 aluminum

Property 6061 Aluminum 6063 Aluminum
Workability Good Excellent
Weldability Excellent Good
Machinability Good Fair
Formability Good Excellent


Corrosion Resistance: A Key Determinant in Alloy Selection

In the world of material selection, especially for industries such as marine, automotive, and construction, a metal’s ability to resist corrosion is often a deal-maker or breaker. Corrosion resistance refers to the ability of a material to prevent or slow down the process of corrosion, thereby prolonging its service life.

Both 6061 and 6063 aluminum alloys boast excellent corrosion resistance thanks to a natural layer of aluminum oxide that forms when the metal is exposed to air. This protective layer shields the underlying metal from exposure to corrosive elements.

However, there are slight variations in their corrosion resistance capabilities due to the different alloying elements present. 6061 aluminum, with its slightly higher copper content, can be more susceptible to corrosion in certain environments than 6063. It is crucial to note that while the copper content enhances the alloy’s strength, it can decrease its resistance to corrosive elements, especially in marine environments.

Overall, 6061 Aluminum offers good corrosion resistance, while 6063 Aluminum is excellent in terms of corrosion resistance.


Applications: Where do 6061 and 6063 Fit in?

Custom Wheel made with 6061 aluminum

Understanding the key characteristics of 6061 and 6063 aluminum helps us appreciate where each alloy fits in the diverse world of aluminum applications.

Table 6: Applications of 6061 and 6063 aluminum

Alloy Applications Reason for Use
6061 Aluminum Aircraft and Yacht Construction High strength-to-weight ratio
  Bicycle Frames Excellent fatigue strength
  Structural Components (Buildings, Bridges) Superior strength and corrosion resistance
  Automotive Parts Good formability, weldability, and corrosion resistance
  Heavy-duty Structures High mechanical properties
6063 Aluminum Architectural Applications (Window Frames, Door Frames, Roofs) Excellent workability and aesthetics
  Decorative Trims Excellent formability
  Heat Sinks Great thermal conductivity and extrudability
  Furniture Frames Superior finishing and resistance to corrosion
  Aluminium Extrusion Profiles Exceptional ability to be extruded into complex shapes


6061 vs 6063: Which One Should You Choose?

The choice between 6061 and 6063 aluminum fundamentally depends on your specific project needs. Each alloy excels in different areas and is designed for different applications.

The 6061 aluminum alloy stands out due to its high strength and resistance to stress. It’s an excellent choice for applications that require durability and structural stability, such as in the construction of buildings, bridges, and heavy-duty structures. The hardness and strength of 6061 also make it suitable for applications like bicycle frames, automotive parts, and aircraft construction, where the material must withstand significant wear and tear.

On the other hand, the 6063 aluminum alloy is known for its excellent formability and aesthetic appeal. This makes it an ideal choice for applications where aesthetics are crucial. Architectural applications such as window and door frames, decorative trims, and furniture frames often employ 6063 due to their visual appeal and workability. Furthermore, its ability to conduct heat efficiently makes it a popular choice for heat sinks.

Table 7: Key differences and suggested applications for both alloys

Characteristic 6061 Aluminum 6063 Aluminum
Strength High Medium
Workability/Formability Good Excellent
Corrosion Resistance Excellent Good
Applications Structural and mechanical applications, aircraft and yacht construction, bicycle frames, automotive parts Architectural and aesthetic applications, window and door frames, decorative trims, heat sinks, furniture frames


Prolean’s Aluminum Machining & Fabrication Services: Ensuring Unparalleled Precision

Prolean is a leading name in the realm of aluminum machining and fabrication services. Our experienced team of experts leverages advanced technology to deliver unparalleled precision, whether you choose 6061 or 6063 aluminum for your project.

At Prolean, we understand that the choice between 6061 and 6063 is critical, and we’re committed to providing expert guidance based on your project requirements. Our fabrication services encompass a range of processes, including cutting, bending, and assembling. Using state-of-the-art machinery, we can ensure accurate, high-quality results, maintaining the inherent properties of the aluminum.

Moreover, our machining services provide further value. With advanced CNC technology, we can perform milling, turning, drilling, and tapping operations with absolute precision. Our rigorous quality control measures ensure that every piece we produce meets the highest industry standards.

Whether you need 6061 or 6063 aluminum machined or fabricated, Prolean’s services offer unparalleled quality and precision. Our expert team, combined with our advanced technology and processes, ensures the successful realization of your project, regardless of its complexity.


Summing Up

The choice between 6061 and 6063 isn’t a one-size-fits-all answer. Instead, it requires a keen understanding of the project at hand and the specific qualities that the application demands. The effectiveness of these alloys depends greatly on their intended use, from structural components that demand the strength of 6061 to aesthetic applications that benefit from the workability and finish of 6063.

Ultimately, it’s important to consider your unique needs, whether that’s strength, formability, corrosion resistance, or aesthetics. Moreover, getting expert assistance, like the services provided by Prolean, can help ensure that the most suitable alloy is chosen for your specific needs, guaranteeing a successful project outcome.



What is the primary difference between 6061 and 6063 aluminum?

The key difference lies in the strength and workability. 6061 aluminum is renowned for its high strength and durability, making it suitable for heavy-duty applications. On the other hand, 6063 aluminum excels in formability, making it ideal for applications that require intricate shapes and excellent finish.

Is 6061 or 6063 aluminum more resistant to corrosion?

Both 6061 and 6063 offer good resistance to corrosion. However, 6061 aluminum generally has superior corrosion resistance, making it a better choice for applications exposed to harsh weather conditions or corrosive environments.

Can 6061 and 6063 aluminum be welded?

Yes, both 6061 and 6063 aluminum can be welded. However, 6061 typically responds better to welding than 6063, which may lose some strength in the heat-affected zones.

What are the typical applications of 6061 and 6063 aluminum?

6061 aluminum is typically used in heavy-duty structures, aircraft and yacht construction, and bicycle frames due to its high strength. In contrast, 6063 aluminum is often used in architectural and aesthetic applications, like window and door frames, and decorative trims due to its superior formability and aesthetic appeal.

Does Prolean offer services for both 6061 and 6063 aluminum?

Yes, Prolean offers a range of aluminum machining and fabrication services for both 6061 and 6063 aluminum, ensuring high precision and quality in every project.


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