Therefore, when {HEAD ~ the cutting edges} of {TAIL ~ the burnishing section} are configured with the same profile as the cutting edges of the reamer section, the burnishing section is in the form of a backward reamer section 
of
Therefore , when { HEAD ~ the cutting edges } of { TAIL ~ the burnishing section } are configured with the same profile as the cutting edges of the reamer section , the burnishing section is in the form of a backward reamer section
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH