Abstract: 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.

Abstract: A self-tapping screw structure includes a threaded rod having one end provided with a cap head, and the other end of the threaded rod is formed with two blades respectively located at two sides of the central point of the threaded rod. Each of the two blades has an extended scrap escaping groove. One of the two blades is provided with a slow cutting portion located adjacent to the central point of the threaded rod and lower than the surface of the second blade, thereby greatly increasing the tapping velocity of self-tapping screw structure.