0.187” Minimum Bore (CNC Qualified to +/-0.0005”), 5/8” Reach Length, 3/16” Shank Diameter, and 2.000” OAL (CNC Qualified to +/-0.001”). A full length precision ground locating flat assures accurate tool location. Cutting edges blend to eccentric neck so as to minimize chip accumulation. These are quality tools CNC ground in the USA on Ceratizit Micrograin Carbide material.