{HEAD ~ The radially inner ends} of the frustoconical surfaces are directed toward {TAIL ~ a first end} of the fastener, and the diameter of the radially inner end of the frustoconical surface away from the first end of the fastener is less than the radially outer diameter of the other frustoconical surface 
are directed toward
{ HEAD ~ The radially inner ends } of the frustoconical surfaces are directed toward { TAIL ~ a first end } of the fastener , and the diameter of the radially inner end of the frustoconical surface away from the first end of the fastener is less than the radially outer diameter of the other frustoconical surface
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL REL REL 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 OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH