{HEAD ~ Each} of the first and second end surfaces includes {TAIL ~ an upper portion} connected to a respective one of the first and second cutting edges, and a lower portion connected to the upper portion by a concave transition portion, wherein the lower portion is recessed axially inwardly relative to the upper portion 
includes
{ HEAD ~ Each } of the first and second end surfaces includes { TAIL ~ an upper portion } connected to a respective one of the first and second cutting edges , and a lower portion connected to the upper portion by a concave transition portion , wherein the lower portion is recessed axially inwardly relative to the upper portion
HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH