4-Pc. Three-Flat Step Drill Bit Set, High Speed Steel, 28 Hole Sizes, 1/8" to 1-3/8"

Step drill bit sets contain multiple bits in different sizes for creating holes in a range of sizes. These cone-shaped bits have steps of increasing diameter marked along their cutting head. As each bit is pushed into a piece of sheet metal or other thin material, each step on the bit widens the hole. The bits also have a self-starting split point that prevents the bits from moving, or walking, when starting to drill, which eliminates the need for using a center drill to create a starter hole before drilling.