The inner periphery of {TAIL ~ the washer bites} into {HEAD ~ the shank} to prevent it from dislodging 
The inner periphery of { TAIL ~ the washer bites } into { HEAD ~ the shank } to prevent it from dislodging
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH