Drill having helical flute for discharging cutting fluid

摘要

A metal cutting drill includes a shank having cutting edges at a front end and helical flutes extending rearwardly from respective cutting edges for conductive cutting fluid away from the front end. The cross-sectional area of each flute, as seen in a plane oriented non-perpendicular to an axis of rotation of the drill, becomes progressively smaller in a rearward direction. A helix angle defined by each flute becomes progressively smaller in the rearward direction. An angle formed between the plane and another plane oriented perpendicular to the axis equals the helix angle at the location where the planes intersect each other and the axis.