{HEAD ~ The nut} has a first end with the internal threads and a second end with {TAIL ~ an inwardly directed shoulder} 
{ HEAD ~ The nut } has a first end with the internal threads and a second end with { TAIL ~ an inwardly directed shoulder }
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL