US Patent 8192124 Self-drilling screw

Disclosed is a screw for hard wood, comprising a screw tip (3) with two cutting edges (5) that extend approximately parallel to each other and perpendicular to the longitudinal axis of the screw. The cutting angle of the cutting edges amounts to about 90°. A centering tip (7) which slightly protrudes from the two cutting edges (5) is embodied in the extension of the longitudinal axis of the screw. Said centering tip (7) prevents the screw from deviating to the side at the beginning of the drilling process.