Why Aluminum?
Fast cuts, lower tooling costs
1/3 weight of steel
Natural oxide protection
Great for heat sinks
Anodizing, powder coat, etc.
Affordable with great properties
Common Alloys
Good all-around. Excellent machinability. Start here if unsure.
Best for: General purpose, structural, fixtures
~2x stronger than 6061 but more expensive.
Best for: Aerospace, high-stress parts
High strength, excellent fatigue resistance. Poor corrosion.
Best for: Aircraft structures
Excellent corrosion resistance, especially saltwater.
Best for: Marine, chemical environments
6061 vs 7075
| Property | 6061-T6 | 7075-T6 |
|---|---|---|
| Strength | Good | Excellent (2x) |
| Machinability | Excellent | Good |
| Corrosion | Excellent | Good |
| Weldability | Excellent | Poor |
| Cost | Lower | Higher (~30-40%) |
Rule of thumb: Use 6061 unless you specifically need 7075's strength.
Surface Finishes
As Machined
Standard finish, visible tool marks
Bead Blast
Uniform matte, hides tool marks
Anodize Type II
Decorative colors, corrosion resistant
Anodize Type III
Hardcoat, excellent wear resistance
Powder Coat
Durable paint, wide colors
Chromate (Alodine)
Corrosion resistance, paint adhesion