In either case, {HEAD ~ the head} of the fastener may have {TAIL ~ a tapered forward surface portion} for engagement with the walls of an access bore in an object to be fastened to the workpiece 
have
In either case , { HEAD ~ the head } of the fastener may have { TAIL ~ a tapered forward surface portion } for engagement with the walls of an access bore in an object to be fastened to the workpiece
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH