The bit assembly comprises an elongated housing having a first end adapted for engagement with the drill and a second end, including {HEAD ~ the cutting cone}, for engaging {TAIL ~ the material} to be drilled 
for engaging
The bit assembly comprises an elongated housing having a first end adapted for engagement with the drill and a second end , including { HEAD ~ the cutting cone } , for engaging { TAIL ~ the material } to be drilled
OTH OTH OTH OTH OTH OTH 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 REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH