Step Drill Bit Set, Number of Flutes: 2, Material: High Speed Steel, Finish: Black Oxide, Shank Size: 1/4 inch, 3/8 inch, Overall Length: 2-1/32 inch, 2-13/64 inch, 2-61/64 inch, 3-7/64 inch, 3 inch, 3-21/64 inch, Number of Holes: 38, Point Shape: 3 Flat Shank, Thickness: 1/8 inch, 5/32 inch, 3/16 inch, Applicable Materials: Mild Steel, Copper, Aluminum, Brass, Wood, Plastics, Includes: (1) 48-89-9201 (1/8 - 1/2 inch x 1/32 inch), (1) 48-89-9204 (3/16 to 7/8 inch x 1/16 inch), (1) 48-89-9206 (3/8 inch, 1/2 inch x 1/16 inch), (1) 48-89-9207 (7/8 inch Single Hole), (1) 48-89-9208 (1/2 - 1 inch x 1/16 inch), (1) 48-89-9209 (7/8 inch, 1-1/8 inch), (1) Hard Plastic Case, Number of Pieces: 6, Size Range: 1/8 - 1-1/8 inch, Applications: For Drilling Small and Large Diameter Holes