What Is 6063 Aluminum Alloy?
6063 aluminum alloy—often called the “architectural alloy”—is the most widely used aluminum alloy for extrusion worldwide. As a 6000 series magnesium-silicon alloy, 6063 offers an unmatched combination of excellent extrudability, good corrosion resistance, attractive surface finish, and sufficient strength for a vast range of structural and decorative applications.
From window frames and door profiles to curtain walls and heat sinks, 6063 aluminum is the backbone of the architectural aluminum industry. Its ability to form complex cross-sections with tight tolerances and smooth surfaces makes it the preferred choice for over 70% of all aluminum extrusions produced globally.
6063 Aluminum Chemical Composition
| Element | Content (%) |
|---|---|
| Aluminum (Al) | Balanced |
| Magnesium (Mg) | 0.45 – 0.9 |
| Silicon (Si) | 0.20 – 0.6 |
| Iron (Fe) | ≤ 0.35 |
| Copper (Cu) | ≤ 0.10 |
| Manganese (Mn) | ≤ 0.10 |
| Chromium (Cr) | ≤ 0.10 |
| Zinc (Zn) | ≤ 0.10 |
| Titanium (Ti) | ≤ 0.10 |
The lower Mg and Si content compared to 6061 aluminum (0.8–1.2% Mg, 0.4–0.8% Si) gives 6063 its superior extrudability and surface finish quality. For a full alloy comparison, read our 5052 vs 6061 guide.
Mechanical Properties of 6063 Aluminum
| Property | T5 | T6 |
|---|---|---|
| Ultimate Tensile Strength (MPa) | ≥ 145 | ≥ 205 |
| Yield Strength (MPa) | ≥ 110 | ≥ 170 |
| Elongation (%) | ≥ 8 | ≥ 8 |
| Hardness (HB) | ≥ 60 | ≥ 75 |
Understand what T5 and T6 mean in our detailed guide: Decoding Aluminum Temper Designations.
6063-T5 vs 6063-T6: Which to Choose?
This is one of the most common questions from buyers. Here’s a practical comparison:
| Feature | T5 (Cooled from extrusion + artificially aged) | T6 (Solution heat treated + artificially aged) |
|---|---|---|
| Strength | Moderate | Higher |
| Extrusion Speed | Faster | Slower (additional heat treatment step) |
| Surface Finish | Smoother | May show slight streaking |
| Cost | Lower | Higher |
| Anodizing Quality | Excellent | Good |
| Best For | Architectural profiles, decorative trim | Structural components, load-bearing parts |
Rule of thumb: Use T5 for visible architectural applications where appearance matters most. Use T6 for structural applications where strength is the priority.
Key Properties of 6063 Aluminum
1. Exceptional Extrudability
6063 has the highest extrudability rating of any structural aluminum alloy. It can be extruded into extremely complex cross-sections with thin walls (as thin as 0.7mm), tight tolerances, and excellent surface quality—features impossible with stronger but less extrudable alloys like 6061 or 7075.
2. Outstanding Surface Finish
6063 produces the smoothest as-extruded surface among all aluminum alloys. This makes it ideal for applications where the surface will be anodized, painted, or powder-coated, as the finish quality directly affects the appearance of the final product.
3. Excellent Anodizing Response
6063 aluminum anodizes beautifully, producing clear, bright, and uniform oxide layers. This is why it dominates in architectural applications where color anodizing is required. Learn about surface treatments in our aluminum processing technology guide.
4. Good Corrosion Resistance
While not as corrosion-resistant as 5000 series alloys in marine environments (see alloy comparisons), 6063 provides excellent atmospheric corrosion resistance for building exteriors, making it suitable for most architectural and industrial environments.
Major Applications of 6063 Aluminum
Architectural & Building
- Window and door frames (the single largest application)
- Curtain wall framing systems
- Storefront and entrance systems
- Sunshades and louvers
- Railing and balustrade systems
- Partition frames
Industrial & Electrical
- Heat sinks for LED lighting and electronics
- Electrical conduit and cable trays
- Machine guards and frames
- Conveyor system components
Transportation
- Truck body framing
- Rack and storage systems
- Refrigerated vehicle framing
Furniture & Interior
- Office partition systems
- Display and shelving frames
- Kitchen cabinet framing
6063 vs 6061 Aluminum: Quick Comparison
| Feature | 6063 | 6061 |
|---|---|---|
| Extrudability | Excellent (Rating A) | Good (Rating B) |
| Tensile Strength (T6) | 205 MPa | 310 MPa |
| Surface Finish | Excellent | Good |
| Anodizing Quality | Excellent | Good |
| Machinability | Fair | Good |
| Weldability | Good | Good |
| Complex Sections | Easy | Limited |
| Primary Use | Architectural profiles | Structural components |
For a detailed comparison, see our 6061 vs 7075 and 5052 vs 6061 guides.
6063 Aluminum Extrusion Capabilities
When sourcing 6063 aluminum extrusions, consider these specifications:
- Cross-Section Size: From 10mm to 300mm+ circumscribing circle
- Wall Thickness: Minimum 0.7mm for hollow profiles; 0.5mm for solid
- Length: Up to 12 meters (custom lengths available)
- Tolerances: DIN 17615, EN 755, or custom specifications
- Surface: Mill finish, anodized, powder coated, wood grain, electrophoresis
Frequently Asked Questions (FAQ)
Is 6063 aluminum stronger than 6061?
No, 6061 is significantly stronger than 6063 in the same temper condition. 6061-T6 has a tensile strength of ~310 MPa versus ~205 MPa for 6063-T6. However, 6063 excels in extrudability, surface finish, and anodizing quality. Choose 6061 for structural strength and 6063 for complex profiles and appearance.
Can 6063 aluminum be welded?
Yes, 6063 can be welded using MIG and TIG processes, typically with 4043 or 5356 filler wire. However, welding reduces the strength in the heat-affected zone. For welded structural applications, 6061 may be a better choice. See our aluminum welding wire selection guide.
What is the melting point of 6063 aluminum?
6063 aluminum has a melting range of approximately 615–655°C (1139–1211°F), with a density of 2.69 g/cm3.
Why is 6063 better than 6061 for window frames?
6063 produces smoother extrusions with better surface finish and superior anodizing results. Window frames don’t require the higher strength of 6061, making 6063 the more cost-effective and aesthetically superior choice.
Source 6063 Aluminum from HXM
HXM Aluminum provides complete 6063 aluminum solutions:
- Standard and custom extrusion profiles
- Aluminum tubes, bars, and profiles in T5 and T6 tempers
- Surface treatment: anodizing, powder coating, wood grain transfer
- Custom die design and profile development
- Mill certificates with full traceability
- Fast 7–15 day delivery worldwide
Looking for 6063 aluminum profiles? Contact HXM Aluminum for custom extrusion quotes and technical support.
Last updated: June 2026 | Written by HXM Aluminum Technical Team
