It can add a beautiful touch to wood projects, or tap on most quick disconnect adapters, such as wooden or doors. Made of high-quality steel material, it can create clean and accurate counter holes. Quite hard and strong. The adjustable design allows you to easily change the drill bit. Its spring outer guide belt has chamfering , which makes the high-speed drill concentrate in the center and creates a perfect guide hole; They easier to align holes and get the center every time. Unique design and perfect punching effect. Suitable for the installation of door hinges. Easy to use and install, quick bit replacement, single-handed loading and unloading. When drilling, choose low speed, and suggest 2000R/min -3000R/min. If the speed is too fast, the self-centering drill bit may not be centered and will break. Name:Hinge bit set Quantity:8pcs/set Colour:Silver Material:steel Package Contents: 1 * wrench 7 * Hinge drill bit Only the above package content, other products are not included. Note: Light reflection 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.