Machinability Ratings of Materials

What is Machinability?

Machinability of a material can be defined as the ease with which it can be machined.

The American Iron and Steel Institute (AISI) determined the machinability ratings for a wide variety of materials. They determined this by running turning tests at 180 surface ft/min (sfpm). The AISI then arbitrarily assigned 160 Brinell B-1112 steel a machinability rating of 100%. The machinability rating is determined by measuring the weighed averages of the normal cutting speed, surface finish, and tool life for each material.

Machinability Ratings

_{Note that a material with a machinability rating less than 100% would be more difficult to machine than B-1112 and material with a value more than 100% would be easier.}