The present invention provides a cutter for {HEAD ~ an earth boring system} that has {TAIL ~ a rotary unit} which bores into earth formations to form a hole therein 
has
The present invention provides a cutter for { HEAD ~ an earth boring system } that has { TAIL ~ a rotary unit } which bores into earth formations to form a hole therein
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH