Self-drilling/self-tapping screw

摘要

A self-drilling/self-tapping screw comprises a shank having a plurality of self-tapping thread convolutions thereon and a head on an end of the shank. The shank further includes a longitudinal axis about which the shank rotates and an entering end portion on another end thereof. The entering end portion comprises a sharp pointed tip substantially located on the longitudinal axis of the shank, a first cutting edge has a first acute angle with the longitudinal axis of the shank, and a second cutting edge having a second acute angle with the longitudinal axis of the shank, the second acute angle being smaller than the first acute angle. In an embodiment, a groove is provided in the entering end portion to increase the cutting speed.