6063T5 Vs 6061T5 Aluminum Alloys Key Differences and Uses

Selecting the right aluminum alloy can be challenging given the numerous options available. Among them, 6063-T5 aluminum alloy stands out with its unique advantages, offering excellent surface treatment properties, corrosion resistance, and superior workability. Widely used in construction and structural applications, this article provides an in-depth analysis of 6063-T5 aluminum alloy's characteristics, applications, and a detailed comparison with 6061-T5 to help guide your material selection.

6063-T5 is a medium-strength heat-treatable alloy renowned for its exceptional surface finish, corrosion resistance, and excellent workability. Primarily used in architectural and structural applications, this alloy contains 0.7% magnesium and 0.4% silicon, offering good mechanical properties suitable for various extruded profiles.

The alloy demonstrates excellent extrusion capabilities, enabling production of thin-walled and complex hollow shapes. Standard profiles include flat angles, channels, and hollow circular and square sections. 6063 responds well to polishing, chemical brightening, anodizing, and coloring processes.

• 6063: The alloy designation, part of the 6xxx series (Al-Mg-Si), indicating primary composition of aluminum with magnesium and silicon as main alloying elements.
• T5: The temper designation indicating artificial aging after cooling from high-temperature forming processes (e.g., extrusion), achieving medium strength while maintaining good machinability and surface finish.

• Strength: Lower than 6061 but sufficient for many structural applications
• Corrosion Resistance: Excellent performance in outdoor and marine environments
• Surface Finish: Superior quality, ideal for anodizing
• Machinability: Good performance for cutting, welding and forming

The T5 temper designation describes the heat treatment process applied after forming:

• Cooling from high-temperature forming process (e.g., extrusion)
• Artificial aging to achieve stable mechanical properties

• Medium strength (higher than annealed but lower than T6)
• Good machinability (easier to work than T6)
• Maintained corrosion resistance
• Superior surface finish compared to T6, making it ideal for anodizing

6063 aluminum exhibits exceptional corrosion resistance due to its excellent anodizing capabilities. The anodizing process creates a thicker chemically-bonded oxidized layer that protects against further corrosion while providing an attractive, uniform appearance that can incorporate color pigments without peeling.

Considered a "softer" alloy, 6063-T5 offers excellent machinability and extrudability - making it the most common choice for extrusion applications. As a heat-treatable 6xxx series alloy, it presents some challenges in annealing for complex shapes or severe deformation.

Dimensions must conform to ANSI H35.2M table allowances. For dimensions not covered by this standard, tolerances should be mutually agreed between producer and purchaser and specified in contracts or purchase orders.

Both belong to the 6xxx series (Al-Mg-Si) aluminum alloys with similar compositions but differ in strength, machinability and surface finish.

• 6061-T5: Structural applications, aerospace, automotive and heavy-duty components where strength is critical
• 6063-T5: Architectural applications (doors, windows, railings), heat sinks and piping where surface finish and corrosion resistance are priorities

No, 6063 aluminum is not as strong as 6061. The T6 temper comparison shows:

• Excellent corrosion resistance for outdoor and marine environments
• Superior surface finish ideal for architectural applications
• Good strength-to-weight ratio
• Excellent extrudability for complex profiles

• Lower strength compared to 6061 (not suitable for high-stress applications)
• Softer material more prone to dents and scratches
• Not suitable for high-temperature applications

• Architectural: Window/door frames, curtain walls, railings
• Structural: Piping, roofing, furniture frames
• Transportation: Bicycle frames, trailer components
• Thermal Management: Heat sinks, lighting fixtures