Aluminum is common in CNC machining because it offers a useful balance of low weight, machinability, corrosion behavior, and finishing options. The correct grade still depends on the part function and operating conditions.

Common Grades

  • 6061: A general-purpose grade with balanced strength, corrosion resistance, and machinability.
  • 2024: Higher strength and good machinability, with corrosion and temper considerations.
  • 7075: Very high strength, commonly selected when strength is a primary requirement.
  • MIC-6: Cast tooling plate used where dimensional stability and flatness are important.

Grade and Temper Matter

Different tempers of the same alloy can have different mechanical properties. Where performance matters, specify both the alloy and temper rather than using only the general material name.

Drawing-Based Selection

Consider strength, corrosion exposure, weight, machining features, surface finish, and the required production quantity together. If the drawing already specifies an alloy and temper, that specification should be followed.