| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a hand tap such that when a female screw is formed on a workpiece, a substantially columnar body is accurately inserted into a hole for female screw formation along a center axis of the hole for female screw formation, and the female screw is accurately formed in the hole for female screw formation. <P>SOLUTION: A hand tap 1 is constituted by providing a female screw forming blade 5 on a circumferential surface 4a of one end 4 of a substantially columnar body 3, and a columnar projection 13 which has substantially the same diameter with the cylindrical hole for female screw formation bored in the workpiece is projected on an end surface 4b of the one end 4 of the substantially columnar body 3. When the female screw is formed in the workpiece, the substantially columnar body 3 is guided by the projection 13 along the center line of the hole for female screw formation, and accurately inserted into the hole for female screw formation. <P>COPYRIGHT: (C)2013,JPO&INPIT |
