Step Drill Bit Set, Material HSS, Black Oxide Finish, Number of Pieces 4, Number of Hole Sizes 31, Size Range 1/8 In. to 1-3/8 In., Sizes Included 1/8 In. to 1/2 In., 3/16 In. to 7/8 In., 7/8 In., 7/8 In. to 1-3/8 In., Step Thickness 3/16 In., 5/32 In., 3/8 In., Number of Flutes 2, Shank Size 1/4 In., 3/8 In., Shank Type Three-Flat, Bit Length 2-13/64 In., 3 In., 3-7/64 In., 3-7/64 In.