| 摘要 |
PROBLEM TO BE SOLVED: To provide a threading tool reducing abrasion and tearing and having good durability. SOLUTION: The threading tool has a shaft and cutting sections, and the cutting sections comprising cutting teeth 5 arranged parallelly or spirally in an axial direction and several grooves 6 between the cutting teeth for chips. To provide the threading tool substantially reducing the abrasion and the tearing and having relatively longer durability than conventional threading tools, and to reduce damage of cutting blades of the cutting teeth and reduce breakage even after a long period of use of the cutting tool, the cutting tool in which at least portions of cutting teeth at sloping faces 11 have radial directional undercuts 7 behind respective cutting blades 8 is provided. COPYRIGHT: (C)2003,JPO |
