How to Pick the Right Aluminum Grade
Picking an aluminum grade is about trade-offs. No single alloy does everything best. The right choice depends on what matters most for your part.
Strength vs. Machinability
Stronger alloys are harder to machine. 7075-T6 has the highest strength at 83 ksi. But it takes longer to cut and wears tools faster. 6061-T6 machines faster and costs less. It handles most jobs well at 45 ksi.
If your part faces high loads, pick 7075. If it does not, 6061 saves time and money.
Corrosion Resistance
Parts near salt water or chemicals need good corrosion resistance. The 5xxx series (5052, 5083) is best here. They resist salt spray and harsh chemicals. The 2xxx and 7xxx series have poor corrosion resistance. They need coatings or paint to last.
Cost
6061 is the cheapest common grade. 7075 costs about 30% more. The 2xxx series falls in between. MIC-6 cast plate costs more per pound but machines fast, which can lower total part cost.
6061-T6 is the most popular grade for CNC machining. It is strong, easy to machine, anodizes well, and costs less than 7075.
Quick Decision Guide
- Need strength? → 7075-T6
- Need corrosion resistance? → 5052 or 5083
- Need machinability? → 6061 or 2011
- Need to weld? → 5052 or 6061
- Tight budget? → 6061-T6