| 摘要 |
<p>The tool allows simultaneous drilling and countersinking. It comprises a detachable facing or chamfering cutting (1) secured to the shank of a drill bit (10), so as to work in a conjunction with it. The cutter can have multiple edges and a vertical axial bore to allow sliding on the drill bit. Its sides can have radial bores to accommodate screws (8, 9) securing it to the bit, and arranged in opposite pairs, at the same or different levels.</p> |
