ITEM NAME:Step Drill Cone Drill Bits, High Speed Steel 10 Steps 1/4 to 1-3/8 inch B7F4 Step Drill Cone Drill Bits, High Speed Steel 10 Steps 1/4 to 1-3/8 inch B7F4 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 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 high speed steel with high capability and durability in drilling holes in plastic, aluminum, copper, stainless steel and many other types of sheet metal 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 A drill can alter the use of more than a bit and do not need to replace the drill bit and positioning holes. Weight: 0.3lb APRX. color:gold Material:HSS Package included: 1x Step Drill Bit Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.