| 摘要 |
Two-piece drill bits and methods of manufacturing same provide a preferab ly hexagonal shank, and a drill portion having a proximal end inserted into an axial hole in a distal end of the shank. In a preferred embodiment, at least part of th e area adjacent the proximal end of the drill portion is knurled. Alternative embodiments have wings, polygons, tapers or other irregular shapes, or combinations of same. A variety of means may be employed to mechanically capture the drill portion in the shank. |
