| 摘要 |
A drilling tool for a sinker drill is provided with a drill-bit section (1) or broaching-bit section and a shaft section (2). According to the present invention a reliable drill tool with longer service life is obtained by making the drill-bit section (1) and the shaft section (2) or broaching-bit section and shaft section in two parts joined together by means of a screw joint in such a manner that the shaft section (2) reaches the bottom of the drill-bit section (1) or said broaching-bit section. |
