Step Drill Bit, High Speed Steel, Black Oxide, 3/16 in to 1/2 in Size Range, Straight with Three Flats, 1/4 in Shank Hex Size, 3/8 in Shank Diameter, 2 11/16 in, 2 7/8 in, 3 3/16 in, 3 1/4 in Overall Length, Maximum Drilling Depth 1/8 in, 5/16 in