Taper Length Cutting Edge Material HSSCoPM Measurement Type Inch 5/16 RHS / RHC HSS-CO 8% (M42) 118 Degree Notched Point Cobalt Heavy Duty Taper Length Drill - Straw / Gold Oxide Cleveland List 2513 Cobalt Heavy-Duty Taper Length Drills Tool Diameter 5/16 inch O.A.Length 6-3/8 inch Decimal Equivalent 0.3125 inch Coating Straw-Gold Oxide Shank Type Round Cleveland