6063 Aluminum: Uses, Properties, and Comparison Guide

If you’ve ever admired the clean lines of a modern window frame, a sleek railing, or a bright silver display fixture, you’ve probably seen 6063 aluminum at work. Often called architectural aluminum, 6063 is one of the most commonly used alloys in the 6xxx series thanks to its excellent extrudability, surface finish, and corrosion resistance.

This guide covers everything you need to know about 6063 aluminum—from its composition and properties to common applications, tempers, and how it compares to other popular alloys like 6061.

What Is 6063 Aluminum?

6063 aluminum is a magnesium–silicon (Mg–Si) alloy in the 6xxx series, known for forming easily into complex shapes and maintaining a smooth, bright surface. These characteristics make it ideal for architectural and decorative extrusions where appearance is just as important as strength.

Chemically, 6063 typically contains around 0.6% silicon and 0.9% magnesium, with small traces of iron, copper, and other elements to fine-tune its mechanical behavior.

Chemical Composition of 6063 Aluminum

The combination of magnesium and silicon forms magnesium silicide (Mg₂Si), which gives the alloy its strength after heat treatment.

Key Properties of 6063 Aluminum

6063 is prized for its combination of moderate strength, excellent formability, and superior surface finish. Let’s break down its main characteristics:

1. Density

• 2.70 g/cm³, the same as most aluminum alloys.
• This makes it roughly one-third the weight of steel, enabling lightweight designs.

2. Strength

• Moderate strength compared to other 6xxx alloys.
• T5 temper: ~145 MPa ultimate tensile strength
• T6 temper: ~190 MPa ultimate tensile strength
• Suitable for structural applications that don’t require high load-bearing capacity.

3. Corrosion Resistance

• Excellent resistance to atmospheric and marine environments.
• Commonly used in coastal architectural structures because it resists oxidation and pitting.

4. Formability and Extrudability

• Outstanding—this is why it’s used in intricate extruded shapes like window channels, tubes, and complex frames.
• Manufacturers often prefer 6063 over 6061 when detailed profiles are needed.

5. Surface Finish

• Naturally smooth and bright surface, ideal for anodizing, painting, or powder coating.
• The alloy can achieve a decorative, corrosion-resistant finish that lasts decades.

6063-T5 vs. 6063-T6: Understanding the Tempers

The temper designation tells you how the alloy has been heat-treated, which affects its mechanical properties.

Example:

• A window frame typically uses 6063-T5 for easier fabrication and smoother finish.
• A bicycle frame or automotive trim may use 6063-T6 for added strength and durability.

6063 vs. 6061 Aluminum: What’s the Difference?

While 6063 and 6061 are both 6xxx series alloys, they serve different purposes. Here’s a side-by-side comparison:

Common Applications of 6063 Aluminum

Because of its excellent surface finish and ease of extrusion, 6063 appears across multiple industries:

Architecture:

• Window and door frames
• Curtain walls, railings, and decorative trim

Industrial:

• Heat sinks, conduits, tubing, and machine frames

Transportation:

• Bicycle and trailer frames, automotive trim, marine walkways

Example: The anodized silver framing on modern glass office buildings is often made from 6063-T5 extrusions.

Advantages and Disadvantages of 6063 Aluminum

Technical Data Summary

Why Choose 6063 Aluminum

6063 offers a perfect balance of form, function, and finish. It’s light, durable, corrosion-resistant, and easy to shape—making it a favorite across construction, industrial, and consumer markets.

Whether you’re designing a storefront system, heat sink, or lightweight frame, 6063 delivers performance and visual appeal.

For sourcing and technical assistance, visit:
Metal Exchange Aluminum Products
Our Recycling and Trading Capabilities
Aluminum Association Standards

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FAQs About 6063 Aluminum

Q: What is 6063 aluminum used for?
A: It’s widely used for architectural extrusions, frames, and tubing due to its surface finish and corrosion resistance.

Q: Is 6063 stronger than 6061?
A: No — 6061 is stronger, but 6063 is better for appearance and complex shapes.

Q: Can 6063 be welded?
A: Yes, it welds easily with TIG or MIG using ER4043 or ER5356 filler rods.

Q: What’s the difference between 6063-T5 and T6?
A: T6 is stronger due to heat treatment, while T5 is more formable and ideal for decorative work.

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