| 摘要 |
A drill comprises a solid shank (1) with a first, tip forming end (2) having cutting edges (8, 8'), an opposite second end (3) and a number of flutes (7, 7') corresponding to the number of cutting edges. These flutes extend from the tip end (4) towards the other end (3) and have the purpose of forming and conveying chips from the corresponding cutting edge. On a certain distance from the tip (2) the individual flute (7, 7') turns from a first, chipforming zone (12) with a certain width or cross-sectional area into a second, merely chip-conveying zone (13) with larger width or cross-sectional area. After having been formed in the first zone (12), the chips are given the possibility of dilating in the second zone (13), in order to facilitate chip conveyance. <IMAGE> |
