| 摘要 |
A hollow drill bit of this type is composed of a hollow shank and several cutting inserts fastened to the hollow shank at a peripheral distance from one another and having an abrasive action. To increase the drilling capacity and prolong the service life, each cutting insert has a drop-shaped profile or a similar outline profile in plan view and is arranged with regard to the peripheral shape of the hollow shank in such a way that at least its radially outer side face, at least in its peripheral section adjoining the trailing end of each insert, runs inclined towards the periphery of the hollow shank.
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