Further, {HEAD ~ the annular protrusion second end} can have a series of external threads on its outer surface for threaded engagement with a series of internal threads of {TAIL ~ a nut} 
Further , { HEAD ~ the annular protrusion second end } can have a series of external threads on its outer surface for threaded engagement with a series of internal threads of { TAIL ~ a nut }
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL