SELF DRILLING SCREW STRUCTURE

摘要

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.