Features: ▶Super sharp cutting flute clears chips efficiently and leaves a clean & smooth hole. ▶Easy to use the combination of Hex Key to adjust or disassemble the countersink drill bit and the five-flutes chamfering. ▶Drill bits are precisely fit into the countersink sleeves and the two chamfered flutes enable faster operation and self-clearing drilling on the swarf, making perfectly sized and shaped holes Specification: Shank: 1/4 hexagonal handle Material: high-speed steel 4241 + # 45 steel Suitable for the drilling equipment with a chuck or connector for drilling in hard wood. Chamfer corresponding drill size: 6#/2.38mm 8#/2.78mm 10#/3.175mm 12#/3.56 mm Package List: 4 * Countersink Drill 1 * Hex Wrench Steps for usage: Step1: Rotate the Hex Wrench to adjust the length you need. Step2: Insert the countersink bit into the drill. Please make sure the drill bit is clamped. Step3: Vertical drilling the drill bit during the operation. The depth only needs to allow the screw head to sink below the surface. After-sales Service: If you have any questions or confusion about the Countersink Drill, please feel free to contact us. We are glad to provide you with the best service.