Abstract: A self-drilling screw having a head at one end and a forged drilling end configuration at the other. The drilling end configuration comprises a pair of longitudinally extending flutes which are separated by land portions and which extend through a tapered tip end to form two cutting edges. The forging operation is performed in such a way as to promote complete formation of the tip end and that may be achieved by inhibiting material flow away from that tip end or by promoting extrusion of material towards the tip end. The drilling end portion of the screw is of elliptical cross section having a minor axis in the region of 60 to 80% of the major axis, and a fillet is formed in the base of each flute at the tip end portion of the flute. Each fillet has a flat surface arranged generally parallel to the screw axis and angularly relative to the ajacent cutting edge of the tip end.

Abstract: A drilling and reaming screw is disclosed having a drill tip and a pair of frangible wings as a reaming means. The frangible wings are formed from the shank so that they include inner portions within the shank diameter and outer portions outside the shank diameter. Upon reaching a workpiece of predetermined hardness, the outer portions are adapted to break off from the shank along a line lying entirely beneath the surface of the shank such that no harmful protuberances remain.