PROBLEM TO BE SOLVED: To maintain excavation performance and excavation efficiency over a long period of time by means of an excavation tip, improve lifetime of a tool, and reduce excavation cost per unit depth of an excavation hole.
SOLUTION: Embedding holes 8 are formed at a front end of a tool body 1 which is rotated around an axis line O and advanced to a front end side in the axis line O direction. The excavation tip 5A integrally formed of a buried part 6 with a cylindrical appearance and a blade edge part 7 is provided in each of the embedding holes 8, with the buried part 6 being inserted into the embedding hole 8, and the blade edge part 7 projecting from the embedding hole 8. The excavation tip is attached such that it is freely rotatable around a central axis C of the buried part 6 during excavation and is prevented from coming off to a front end side in the central axis C direction.
COPYRIGHT: (C)2013,JPO&INPIT
