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