Self-threading fastener

Abstract

A threaded fastener in the form of a bolt or screw for recutting damaged threads during installation in a previously threaded bore or for cutting threads in a non-threaded bore. The fastener comprises a threaded shank terminating in a headed end and in a non-threaded frustro-conical lead-in end. A cavity is formed in the shank extending longitudinally from the first shank thread adjacent the frustro-conical lead-in shank end toward the headed shank end. The cavity comprises a slot of obround peripheral configuration having a planar bottom and a depth greater than the depth of the shank threads. At the end of the slot, nearest the lead-in end of the fastener, a radial bore is provided in the shank having a depth up to the longitudinal axis of the fastener shaft and a diameter equal to the diameter of the curved end of the obround slot. The trailing longitudinal edge of the slot comprises a thread cutting edge. The cavity comprises a collecting, retaining, and compacting recess for metal cuttings, from which the cuttings cannot escape.

Dependencies are inferred from the claim text.