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