{TAIL ~ A metal} 1 wherein said {HEAD ~ conical portion} has at least one annular step 
{ TAIL ~ A metal } 1 wherein said { HEAD ~ conical portion } has at least one annular step
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH