1. Professional drilling tools are suitable for installing hinges in the door.2. Hinge for the screw hole of the door and window hinge, positioning accuracy, will not move, sawdust from the drill hole on both sides of the upper side of automatic discharging will not get stuck.3. It can effectively improve drilling efficiency! Product design compact, functional and powerful, it is industry and DIY that need to choose tools.4. A spring-loaded centering guide built in the hole of a door hinge, cabinet hinge, bracket, or hardware where a center hole is required.5. The drill is a high-speed steel material is more difficult, the head of the three-point structure, does not slip. Specification: Bit Material: High Speed Steel Head Material: Brass Shank Size: 1/4" (6.35mm) Hole Size: 1/4" & 5MM Package Includes: 1*Hinged Twist Drill Bits[Note]: when opening the hole according to the corresponding wood hardness adjustment, if softwood, can choose small, if hardwood, choose suitable or large.