Rivet fastener with drilling bit

A self drilling rivet fastener, comprising a rivet casing and a rivet spindle inserted into said rivet casing, said rivet casing having an internal thread extending over at least a part of a length thereof and including a sleeve portion and a stop flange of a larger diameter, said rivet spindle including a bolt-shaped shaft having an external thread over at least a part of a length thereof and corresponding to said internal thread and adapted for threading thereinto and a head unit terminating with a drill bit for producing a hole in a workpiece for receiving the fastener, said internal and external threads being formed such that rotation of said rivet spindle to produce a hole in the workpiece will cause said rivet spindle to thread into said sleeve portion to set the rivet, said flange having shaped surface means on a face thereof facing the workpiece to provide a fitting mount of said rivet casing against the workpiece, said rivet casing being formed with predetermined breaking grooves extending parallel to an axis of the casing over a part of the length thereof starting at said stop flange, said rivet casing further including radially extending slits at a free end thereof, said grooves merging into said radially extending slits.