{HEAD ~ The burnishing section} is operative to upset {TAIL ~ the material} around the hole, so as to result in a residual stress beneficial to the hole 
is operative to upset
{ HEAD ~ The burnishing section } is operative to upset { TAIL ~ the material } around the hole , so as to result in a residual stress beneficial to the hole
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH