Neiko 10197A Step Drill Bit Set, 5 Pc Step Bit For Metal, 50, Step Up Drill Bits The NEIKO 10169A Step Up Drill Bit set is your all in one drill bit set, drill a range of different sizes with a single bit. Looking to expand holes or drill into metal, this drillbit in the shape of a cone has multiple sizes in one. Conical shaped bit that allows you to drill a variety of hole sizes without needing to change between bits. The tip of the drill bit drills the smallest hole and as you step or drill further down the diameter increases as you drill. 1pc of 1/4" Shank: 6 steps (3/16, 1/4, 5/16, 3/8, 7/16, 1/2") 1pc of 1/4" Shank: 13 steps (1/8", 5/32", 3/16", 7/32", 1/4",9/32"5/16", 11/32", 3/8", 13/32", 7/16", 15/32", 1/2") 1pc of 3/8" Shank: 9 steps (1/4, 5/16, 3/8, 7/16, 1/2", 9/16, 5/8, 11/16, 3/4") 1pc of 3/8" Shank: 10 steps (1/4", 3/8", 1/2", 5/8", 3/4", 7/8", 1", 1-1/8", 1-1/4", 1-3/8") 1pc of 3/8" Shank: 12 steps HSS COBALT STEP BIT: Classic stepdrill bit constructed of high-speed steel with cobalt coating for drilling holes in plastic, aluminum, copper, stainless steel, and many other types of sheet metal. Also doubles as a hole expander. TWO FLUTE TRI SHANK: Two-flute design deburrs during drilling, clearing chips faster and allowing particles to escape for clean cut holes. Each step drill bit features a tri-flatted shank for a secure fit into power tool chucks, eliminating slip. MULTIPLE HOLE DRILL BIT: This versatile cone bit can replace 50 individual bits with just 5 pieces in one box. Drill a range of different sizes and holes with a single bit without needing to change between bits. INCLUDES: Four multipurpose dill bit in 1/4-inch shank and 3/8-inch shank and a red blow mold carrying case for easy convenience and storage in your car, garage or shop. 50 SIZES IN 1: 5 stepper bits included. 1 x 6 step bit (1/4? shank; 3/16? - 1/2?), 1 x 13 step bit (1/4? shank; 1/8? ? 1/2"), 1 x 9 step bit (3/8? shank; 1/4" to 3/4"), 1 x 10 step bit (3/8? shank; 1/4? ? 1-3/8?), and 1 x 12 step bit (3/8? shank; 3/16? ? 7/8?).