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