Machinability can be defined as the ease of machining of materials, or the ease with which a metal can be cut, depending on the physical properties and cutting conditions of the material. The materials with higher machinability requires less power to cut, can be processed more quickly, and easier to get a good finish.
The American Iron and Steel Institute (AISI) determined the machinability ratings for a wide variety of materials and assigned 160 Brinell B-1112 steel (AISI No.1112 carbon 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. Based on the rating of 160 Brinell B-1112 steel, the machinability of metal machinability chart is expressed as a percentage.