Patent ID: 8961078
Filing Date: 2015-02-24
Classification: B23C,Y10T

Abstract:
1. A rotary cutting tool in which: a first cutting-chip discharge groove disposed from a tool tip towards a base-end side is formed on an outer periphery of a tool body; a plurality of second cutting-chip discharge grooves, provided along a spiral disposed from the tool tip towards the base-end side so as to intersect with the first cutting-chip discharge groove, are formed on an outer periphery section of the tool body where the first cutting-chip discharge groove is absent; a base-end-side outer periphery cutting edge is formed on an intersection ridge between a rake face of a second cutting-chip discharge groove, which faces a direction of tool rotation, and an outer peripheral surface of the tool body or an outer peripheral relief face formed on the outer periphery of the tool body; wherein an end cutting edge is provided at a tip section of the tool body; a tip-side outer periphery cutting edge is formed on an intersection ridge between the rake face at a tip section of the first cutting-chip discharge groove and an outer peripheral surface of the tip of the tool body or an outer periphery relief face formed on an outer periphery of the tip of the tool body; and the base-end-side outer periphery cutting edge is provided further towards the tool base-end side than the tip-side outer periphery cutting edge.