Drilling screw

Claim 1

A drilling screw having a central axis, a driving head on one end, a drilling tip on the other end, a threaded shank, and a drill section extending axially from the shank toward the tip comprising: at least two axially extending, substantially radially directed flat walls lying in substantially the same plane on opposite sides of the central axis; at least two axially extending straight cutting edges parallel to the central axis provided at the outer edges of said flat walls; at least two inclined cutting edges inclined to the central axis extending from said parallel edges and terminating at a common point, said inclined cutting edges lying in the same plane as said radially directed walls; a tip end formed at the termination of said inclined edges providing a predetermined tip angle; at least two inclined flat relief faces extending from said tip end and adjoining said flat axially extending walls at said inclined edges; at least two first longitudinal flat inclined faces inclined from and adjoining said axially extending flat walls at said parallel edges, and each adjoining one of said relief faces at a respective common edge; at least two second longitudinal flat inclined faces each extending from said tip end and adjoining a respective one of said axially extending walls to form at least two V-shaped flutes extending from said tip end toward said shank, and each second inclined face adjoining a respective one of said relief faces at a respective common edge extending from said tip end; at least two third longitudinal flat inclined faces each positioned between respective ones of said first and second inclined faces and adjoining each of said first and second inclined faces at respective common edges, and each adjoining one of said relief faces at a respective common edge disposed between said tip end and said shank; and at least two protruding reinforcing blocks formed by said longitudinal inclined flat faces, said relief faces and said axially extending flat walls.