{TAIL ~ A central part shaft} 2 of {HEAD ~ the shaft} 2 a has a reduced diameter as shown 
{ TAIL ~ A central part shaft } 2 of { HEAD ~ the shaft } 2 a has a reduced diameter as shown
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH