Patent ID: 8186914
Filing Date: 2012-05-29
Classification: B23C,Y10T

Abstract:
1. A rotary cutting tool having a plurality of helically shaped swarf discharge flutes formed on a periphery of a tool body from a leading end towards a trailing end, and having a peripheral blade formed on an intersecting ridgeline of a rake surface of the swarf discharge flutes and a peripheral face of the tool body; the rotary cutting tool characterized in that a back taper part, on which an outside diameter of the peripheral blade and an inside diameter of the tool body gradually decrease from the leading end of the tool towards the trailing end, is provided to the leading end of the tool body, and the degree to which the outside diameter of the peripheral blade gradually decreases is set to be substantially the same as the degree to which the inside diameter of the tool body on the back taper part gradually decreases, the length of the back taper part is set within a range of 50% to 300% of the maximum diameter of the peripheral blade, the peripheral blade and a bottom blade provided on each intersecting ridgeline of the rake surface of the swarf discharge grooves and a leading end flank face of the tool body are disposed at non-equivalent spacing along the circumferential direction of the tool body.