An end conical portion is formed at {HEAD ~ the apex} of said intermediate conical portion and axially aligned therewith, with the intermediate conical portion having a cone half angle greater than {TAIL ~ the end conical portion} 
An end conical portion is formed at { HEAD ~ the apex } of said intermediate conical portion and axially aligned therewith , with the intermediate conical portion having a cone half angle greater than { TAIL ~ the end conical portion }
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL