{TAIL ~ The cutting edges} of the reamer sections are parallel straight cutting edges or {HEAD ~ helical cutting edges} 
{ TAIL ~ The cutting edges } of the reamer sections are parallel straight cutting edges or { HEAD ~ helical cutting edges }
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD