1、118° X Shaped Opening Design: The stepped drill bit with 118° X shaped opening design is used for more precise positioning and effectively reducing drill bit slippage. 2、Double Spiral Flute: This step drill has double spiral flute, reducing resistance, fast cutting, and unhindered chip removal 3、Hex Shank: This is a step drill with hex shank, which is not easy to slip, stronger, more durable and easy to use 4、Application: Can help expand the existing holes and clean the edges, used for repair and renovation, bridge doors and window, etc. 5、Wide Applications: This is step drill that is widely applicable for handheld drills, drilling machines, milling machines and machining centers, etc.