Types: twist drills, center drills, spotting drills, step drills, taper shank drills, drill bit with coolant holes Types: twist drill bit, center drill bit, spotting drill bit, step drills, taper shank drills, and drill bit with coolant holesSize: standard and non-standardLength: normal length, extra length, or specialMade of tungsten carbide, HSS, HSS-co (m42, m35, and m2)Workpiece: carbon steel ...