Choosing Aluminum for Custom CNC Parts

“Aluminum” describes a family of materials, not a complete purchasing specification. For a custom machined component, the alloy and its condition should match the design requirements before a price or production plan is confirmed.

Compare the requirement before the grade

6061 and 7075 are familiar choices for machined parts. 6061 is widely used as a versatile general-purpose alloy, while 7075 is often considered where higher strength is a design priority. This is a starting point rather than a rule that one grade can replace another. Protolabs' CNC machining guide provides a general comparison of these material families.

Keep the specification complete

When a drawing specifies a temper or material standard, include it with the enquiry. Ask the designer to confirm any proposed alternative. A similar-looking finished part does not establish that two alloys have the same performance.

Describe the finish and working conditions

List any coating, cosmetic surface, mating area or electrical contact requirement. Explain the intended working conditions and identify the critical dimensions. These details belong in the project review alongside the material choice, rather than being added after the parts are made.

A practical enquiry checklist

• Part number and current drawing revision.
• Alloy, specified condition and material documentation.
• Order quantity and important inspection requirements.
• Finish, appearance and any approved alternatives.

See our aluminum machining page or send NUOPIN the part requirements. Material suitability and project terms should be confirmed for the specific component.