'Counterbore Set, With Built-in Pilot, 1/32 In Clearance, Number of Pieces 7, Screw Size #6 to 1/2 In Socket Head Cap Screws, Bore Dia 0.260 to 0.789 In, Pilot Dia 0.169 to 0.531 In, Pilot Length 7/32 to 1/2 In, Shank Dia 7/32 to 1/2 In, Overall Length 3 to 6 In, Cobalt High Speed Steel, Sizes Included #6, #8, #10, 1/4, 5/16, 3/8, 1/2 In'