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