A machinability rating is to be determined for a new work material. For the base material (B1112), test data resulted in a Taylor equation with parameters n = 0.29 and C = 490. For the new material, the Taylor parameters were n = 0.23 and C = 430. Units in both cases are: speed in m/min and tool life in min. These results were obtained using cemented carbide tooling.
(a) Compute a machinability rating for the new material using cutting speed for a 30-min tool life as the basis of comparison.
(b) If the machinability criterion were tool life for a cutting speed of 150 m/min, what is the machinability rating for the new material?