| 摘要 |
A drill for drilling of work pieces, preferably of composite materials, comprising a cylindrical shank portion (11), a first cutting edge (13) in form of an arc of a circle arranged in the cutting end of the drill and a second cutting edge (16) perpendicularly connected thereto. The edges (13,16) are preceded in the rotational direction by a third cutting edge (14) which during the drilling cuts away the material radially inside a circular groove which is cut by the first and the second cutting edges (13,16). |
