| 摘要 |
PURPOSE: A manufacturing method of a drill is provided to easily obtain a drill having a desired shape by preparing a mold and fastening members and to improve productivity and work efficiency by reducing manufacturing processes and work time. CONSTITUTION: A drill is manufactured by the following procedure. A handle part(11) and a blade part(12) are formed by cutting a cylindrical pipe. A mold(2) is placed in a base material(10). Three fastening members(3) of which inner face is tapered in an angle the same as the taper angle of the mold, the inner front end is formed in an arc shape, and the upper end is upwardly and downwardly inclined are fastened with the base material by lifting down a pressurizing body(4) while the base material is retrained and pressurizing the fastening members toward the center. Thus, inner and outer diameters of the base material become larger as going to the end of the handle part from the end of the blade part. Thereafter, the base material is processed by making the outer diameter become smaller as going to the end of the handle part from the end of the blade part. Finally, a cutter(13) is formed in the blade part. Therefore, a drill is obtained.
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