| 摘要 |
A drill comprising a solid shank with a first, tip-forming end having cutting edges on opposite second end and a number of flutes corresponding to the number of cutting edges. The flutes extend from the tip end towards the other end and have the purpose of forming and conveying chips from the corresponding cutting edge. At a predetermined distance from the tip, each individual flute turns from a first, chip-forming zone with a predetermined width or cross-sectional area into a second, merely chip-conveying zone with a larger width or cross-sectional area. After having been formed in the first zone, the chips are given the possibility of dilating in the second zone, in order to facilitate chip conveyance.
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