In the arrangement of FIG 8 it may be desirable to provide {HEAD ~ increased relief} behind {TAIL ~ each primary cutter} 21 to reduce the area of wear flat which develops behind the cutting edge as the cutter wears down 
In the arrangement of FIG 8 it may be desirable to provide { HEAD ~ increased relief } behind { TAIL ~ each primary cutter } 21 to reduce the area of wear flat which develops behind the cutting edge as the cutter wears down
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH 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