Choosing the right aluminium alloy is critical for the success of your project. The two most commonly used extrusion alloys — 6063 and 6061 — serve different purposes. Understanding their differences will help you make the right choice.
6063 Aluminium Alloy — The Architectural Alloy
6063 is the most popular alloy for aluminium extrusion, often called the "architectural alloy." It contains magnesium (0.45-0.9%) and silicon (0.2-0.6%) as primary alloying elements.
Key Properties
- Excellent surface finish quality — smooth, consistent, ideal for anodizing
- Good corrosion resistance — performs well in coastal and humid environments
- Moderate strength — yield strength of 170-215 MPa (T5/T6 temper)
- Outstanding extrudability — can form complex shapes with thin walls
- Easy to anodize and powder coat
Best For
- Window and door frames
- Curtain wall profiles
- Decorative architectural elements
- Furniture and display systems
- Electrical conduit and bus bar housings
- Irrigation pipes
6061 Aluminium Alloy — The Structural Alloy
6061 is a high-strength alloy containing magnesium (0.8-1.2%), silicon (0.4-0.8%), and copper (0.15-0.4%). The addition of copper significantly increases its strength.
Key Properties
- High strength — yield strength of 240-275 MPa (T6 temper)
- Excellent weldability — retains strength after welding
- Good corrosion resistance — though slightly less than 6063
- Good machinability — works well with CNC operations
- Less extrudable than 6063 — limited to simpler cross-sections
Best For
- Structural beams and columns
- Machine frames and fixtures
- Automotive and marine components
- Bicycle and motorcycle frames
- Aircraft fittings
- Heavy-duty industrial applications
Head-to-Head Comparison
| Property | 6063-T6 | 6061-T6 |
|---|---|---|
| Yield Strength | 215 MPa | 275 MPa |
| Tensile Strength | 240 MPa | 310 MPa |
| Hardness (Brinell) | 73 | 95 |
| Elongation | 12% | 12-17% |
| Thermal Conductivity | 200 W/m·K | 167 W/m·K |
| Extrudability | Excellent | Good |
| Surface Finish | Superior | Good |
| Weldability | Good | Excellent |
| Cost | Lower | Higher |
Which One Should You Choose?
Choose 6063 when:
- Appearance matters (visible architectural elements)
- You need complex cross-sectional shapes
- Anodized or powder-coated finish is required
- Moderate strength is sufficient
Choose 6061 when:
- Structural integrity is the top priority
- The profile will bear significant loads
- Welding is required in the final assembly
- Surface finish is secondary to strength
Can't decide? At Alument Industries, our engineering team can recommend the optimal alloy grade for your specific application. Contact us with your project requirements for expert guidance.