Aluminum is light, strong for its weight and easy to machine. Picking the right alloy balances strength, finish and cost.
Common grades
- 6061-T6 — the all-rounder for machined parts.
- 6063 — extrusions with a smooth anodized finish.
- 7075-T6 — high strength for demanding parts; more expensive.
- 5052 — good formability for sheet metal.
- ADC12 / A380 — die-casting alloys.
Finishing
Anodizing adds corrosion resistance and color; hard anodizing adds wear resistance. Casting alloys anodize less evenly, so powder coating is often chosen instead.
Verify the grade
Ask for a material certificate and spot-check with a handheld analyzer on important orders.
Tempers explained
The suffix after the alloy number describes how it was treated. T6 means solution heat-treated and artificially aged — the common strong condition for 6061 and 7075. T5 is cooled from extrusion and aged, typical for 6063 profiles. H32 and similar codes apply to non-heat-treatable alloys like 5052 that are strengthened by cold work.
Cost comparison
Roughly, 6061 and 6063 are the economical choices; 5052 is similar for sheet; 7075 typically costs noticeably more and is harder to source in small sizes. Machining time and finishing often matter more to part cost than the alloy price itself.
Anodizing quality checks
- Color match against an approved sample under D65 light.
- Coating thickness — commonly 8–15 μm for decorative Type II anodizing.
- Sealing quality and resistance to staining.
- No burns, streaks or rack marks on visible faces.
