| 摘要 |
In a twist drill comprising a shank, in addition to at least one helical, chip transporting flute, also a cutting insert (3) is included with at least one cutting edge (5), located between a front or top surface (6) and a flank surface (7), which extends at an angle to a reference plane intersecting the centre axis of the drill shank. In connection with at least a part of the cutting edge (5), a second flank surface (9) is provided, which extends at another angle in relation to said reference plane than the first-mentioned flank surface (7). <IMAGE> |
