From the foregoing, it will be apparent that the present invention brings to the art a new and improved drill 10 with {HEAD ~ body} 13 with {TAIL ~ length L} which is at least four times the diameter D of tip end portion 14 
From the foregoing , it will be apparent that the present invention brings to the art a new and improved drill 10 with { HEAD ~ body } 13 with { TAIL ~ length L } which is at least four times the diameter D of tip end portion 14
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 OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH