Self cutting screw with threaded shaft - has drilling point and swarf channel recessed in vicinity of cutting edge

摘要

Self-cutting screw (10) for fixture of at least one workpiece of lesser hardness to another with greater hardness. The screw has a threaded shaft (11, 12) and a drilling point (14) with at least one swarf channel connecting (16) to a cutting edge. The swarf channel, in the vicinity of the cutting edge has a recess which breaks through its rear edge and/or the side wall adjacent to that edge. This swarf channel leads with its rear and/or its other side, or its other wall surfaces (17, 18) into the recess spirally and continually. It issues tangentially on to the cylindrical outer circumference surface of the screw.