Step Bits For Stainless Steel, Metal, Wood, And Plastic Are Included In The Each step drill bit manufactured by NEIKO comes with precision manufacturing and is built with high-grade high-speed steel. Our step bits, or known as unibits, come with a titanium coating that promote the strength and cutting power of each of these drill bits. In this 3 piece set, you get a total of 31 step sizes to create clean holes in metals, plastic and wood. The spiral grooved design deburrs faster and gives you clean cuts every time. Each bit set is engineered for faster drilling and you can have confidence in knowing you will get the job done with accuracy and efficiency with bits that truly perform. Need a center punch to start your hole drilling? Be sure to check out the 02638A 5" Center Punch and the 02639A 6" Center Punch. PREMIUM STEP BIT: Each unibit is constructed of industrial high-speed steel with a titanium nitride coating for durability and strength to punch and drill clean holes in materials like plastic, aluminum, wood, copper, stainless steel, and other types of sheet metal. STEP DRILL BIT FOR METAL: With a split point tip that accelerates cutting speed while preventing angled walking away from center line of bore, drilling holes in metal is fast, efficient, and clean. SPIRAL DESIGN: The two-flute spiral grooved design deburrs chip, dust and debris for clearance and smooth cutting. With 31 step sizes, each hole made with these step bits will be precise. QUICK-CHANGE: The 1/4-inch hex shank makes for easy, convenient, and quick stepper bit switches and is compatible with impact ready power tools. INCLUDES: Each bit set comes with 3 drill bits of a combined 31 sizes to add to your drilling arsenal: 13 step drill (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-inch) 6 step drill (3/16, 1/4, 5/16, 3/8, 7/16, 1/2-inch) and 12 step drill (3/16, 1/4, 5/16, 3/8, 7/16, 1/2, 9/16, 5/8, 11/16, 3/4, 13/16, 7/8-inch).