Drill pilot hole and tapered Countersink for wood screws. Carbide Tipped for long lasting results in hard wood, plywood, plastics, etc, #55272, (D) hex shank: 1/4, D1: 1/2, D2: 1/8, for wood screw size: 6, replacement HSS M2 drill (included): 630-22655272 replacement carbide Tipped Countersink with slow spiral HSS M2 drill for #6 size screw 1/8 drill DIA x 1/4 hex shank for #55227 adjustable no-thrust Countersink