Drill Bit, Step Drill Bit, Drill Bit Material High Speed Steel, Size Range 4 to 12mm, Drill Bit Sizes Included 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, Shank Size 1/4 In., Number of Hole Sizes 9, Step Thickness 1/32 In., Drill Bit Finish TiN, Number of Flutes 1, Shank Shape Hex, Overall Length 3-1/4 In., Impact Rated No