Insert having an expandable split locking collar and method of using same

Claim 1

IN COMBINATION, A WORKPIECE HAVING A THREADED BORE WITH A FASTENER COMPRISING: A CYLINDRICAL BODY HAVING EXTERNAL THREADS ENGAGED WITH THE THREADS OF SAID WORKPIECE BORE, SAID BODY BEING PROVIDED WITH A THREADED BORE AND A COUNTERBORE; SAID BODY HAVING A HEAD PORTION DEFINED BY A PLURALITY OF SEGMENTS SEPARATED BY SLOTS, SAID SEGMENTS BEING PROVIDED WITH EXTERNAL LONGITUDINAL SERRATIONS, AT LEAST A PORTION OF WHICH ARE EMBEDDED INTO THE WALL OF SAID COUNTERBORE, ONLY THE EDGE OF EACH SEGMENT OPPOSITE THE DIRECTION OF THREADING INTO SAID BORE BEING OUTWARDLY AND RADIALLY DEFORMED, SAID SEGMENT EDGES BEING INITIALLY UNEXPANDED; DEPRESSIONS IN THE WALL OF SAID BORE FORMED BY THE RADIAL EXPANSION OF SAID SEGMENT EDGES, SAID DEPRESSIONS ACCOMMODATING SAID SEGMENT EDGES, AT LEAST ONE PORTION OF SAID SEGMENT EDGES SO AS TO ABUTMENT MEANS ENGAGED BY SAID SEGMENT EDGES SO AS TO RESIST ROTATIONAL MOVEMENT OF THE INSERT RELATIVE TO THE WORKPIECE OPPOSITE TO THE DIRECTION OF THREADING.