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