CHIP SEGMENTING TOOL FOR TAPPING, AND FEMALE SCREW WORKING METHOD

摘要

PROBLEM TO BE SOLVED: To certainly segment a chip without damaging strength of a female screw even when the female screw is tapped for a material with high malleability. SOLUTION: By pressing a cutting part 14 of the chip segmenting tool into a lower hole 22 prior to a tapping, chip segmenting grooves are cut in an inner peripheral surface of the lower hole 22 by a plurality of groove cutting edges 16 with triangular cross section. Thus, even if a workpiece 20 is a material with high malleability, the chip in tapping is certainly segmented by the chip segmenting grooves and sufficiently discharged. Continuous twisting about a tap for a long time is prevented, or an accident that a chip is meshed and a cutting tap damages is prevented, and cleaning or the like of the chips is facilitated. COPYRIGHT: (C)2005,JPO&NCIPI