Abstract:Plunge milling can reduce the radial cutting force, the deformation of the workpiece, the machine tool power consumption, and cut diffi cult-to-cut materials with great effi ciency. The application of plunge milling is more and more widely. In view of the characteristic of machinability of precipitation hardening stainless steel PH13-8Mo,an experiment platform for cutting force testing is established, and the experiment is designed by the orthogonal methods. The plunge milling force model of PH13-8Mo is built by multiple linear regression on the basis of experiment data. The changing law of cutting force is studied. The research supplies important reference to the research on the plunge milling of precipitation hardening stainless steel.