BOSCH Step Drill Bit, 1/8 to 1/2 in Drill, 13 Hole, 1/8 in Minimum Hole, 1/2 in Maximum Hole, 3 in Overall Length, 1/4 in Shank Diameter, Titanium, Finish: Titanium-Coated, Applicable Materials: Aluminum, Brass, Cast Iron, Copper, Ducts, Plasterboard, Plastic, Plexiglass, PVC, Sheet Metal, Stainless Steel, Steel, Veneers, Vinyl Siding, Wood, Additional Information: 1/32 in H x 1/8 in D Step, 2 in L Flute