{HEAD ~ The shoulder} has {TAIL ~ a front end} abutting the stem annular flange and a rear end abutting the nut retaining ring 
{ HEAD ~ The shoulder } has { TAIL ~ a front end } abutting the stem annular flange and a rear end abutting the nut retaining ring
HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH