A New Type of Non-Chisel-Edge Shallow-Drill for Machining High Manganese Steel

A new type of non-chisel-edge shallow-drill is developed for machining high manganese steel, which is a typical hard-to-machine material. The marked characteristic of the drill is that the cutting edge is non-chisel-edge, consisting of a section of straight line and a part of curve nearby the center. The characteristics of machining performance of this drill are analyzed. Measures adopted in design for improving cutting performance and prolonging tool life are also presented. Applied example indicates that this new drill has good cutting performances and long life. Compared with common twist drill, the axial thrust cutting force of this tool is reduced 30~50 percent.