How to choose mechanical parts material ah?
The performance of the various materials should be very familiar, and then consult the manual to see what general use in the area.
Different parts require different, and some require strong wear resistance, and some require high strength, and some requirements of the surface friction is small, the specific requirements for each part to find out, and then according to the material wear resistance, strength and other physical properties selected
You can refer to other people to design similar products, assembly map material selection, individual you need special requirements of their own design.