Choose material for the job the part must do

Metals

Aluminum, stainless steel and other alloys each balance weight, corrosion behavior, strength and machinability differently. Specify the exact grade where it matters.

Polymers

Engineering plastics differ in stiffness, wear, moisture response, temperature capability and appearance. Printed and molded versions of a named polymer may behave differently.

Finish and testing

Coating, texture and inspection requirements belong in the same conversation as material choice. Include service conditions and the failure modes you need to avoid.