high speed steel with high capability and durability in drilling holes in plastic, aluminum, copper, stainless steel and many other types of sheet metal EASY DRILLING: Two-fluted design provides faster, smoother cutting; Provided with small pressure and the sets can cut through wood, sheet metal, steel and other surfaces step drill bit with 10 step sizes: 1/4 inch, 3/8 inch, 1/2 inch, 5/8 inch, 3/4 inch, 7/8 inch, 1 inch, 1-1/8 inch, 1-1/4 inch, 1-3/8 inch Tri-flatted shank of step drill fits into drill chuck of power tools securely and avoids slide Mainly used for drilling thin steel within 3mm and it can be completed a one-time processing according to the need to process different diameter holes, Weight: 0.3196702799 Pounds, Manufacturer: Ehwisbe