Relationship Between Cutting-Edge Hardness and Tool Life for Alloy-Steel Bit in Machine Boring of MDF

Tool-life tests in the machine boring of MDF were performed with four bits from an alloy-steel bit having the same tool geometry but different cutting-edge hardness from each other. The experimental data on the effects of the cutting-edge hardness of the bit upon both the progression of tool wear and the variation of cutting resistance (both torque and thrust) were obtained. Furthermore, cutting temperatures in the machine boring of MDF were estimated from the data for the cutting-edge hardnesses of the bits. After studying these data, the quantitative relationship between the cutting-edge hardness and tool life was determined by the extended Taylor's tool-life equation and some considerations were done about the application.