Feature:1. The positioning accuracy is high, it will not move, and the chip will be automatically discharged from the holes on both sides of the upper of the drill bit without jamming the drill bit.2. These hinged drill tools are made of aluminum alloy, which is strong and durable.3. The hinge drills are simple in structure, easy to operate and easy to install. Come with different specification of drill bot to satisfy your needs.4. Widely used in woodworking door and window hinges, it will be automatically removed from these 2 side holes.5. This aluminum alloy hinged drill has a hex handle with a incisive bit and a long service life.Specification:Item Type: Hinge Drill Bit.Material: Aluminum alloySpecification: 5/64in;7/64in;9/64in;9/64in;11/64in;5in;13/64in;1/4inA twist drill for each hinge drillHole Size: 5/64in: Hole Diameter: Approx. 2mm / 0.1in, Self-tapping Screw: Approx. 2 ~ 2.8mm / 0.1 ~ 0.1in7/64in: Hole Diameter: Approx.2.8mm / 0.1in, Self-tapping Screw: Approx. 3 ~ 3.5mm / 0.1 ~ 0.1in9/64in: Hole Diameter: Approx.3.5mm / 0.1in, Self-tapping Screws: Approx. 4 ~ 4.5mm / 0.2 ~ 0.2in9/64in: Hole Diameter: Approx.3.5mm / 0.1in, Self-tapping Screws: Approx. 4 ~ 4.5mm / 0.2 ~ 0.2in11/64in: Hole Diameter: Approx.4.5mm / 0.2in, Self-tapping Screw: Approx. 5 ~ 5.5mm / 0.2 ~ 0.2in13/64in: Hole Diameter: Approx.5.1mm / 0.2in, Self-tapping Screw: Approx. 5.6 ~ 6.1mm / 0.2 ~ 0.2in1/4in: Hole Diameter: Approx.6.3mm / 0.2in, Self-tapping Screw: Approx. 6.8 ~ 7.3mm / 0.3 ~ 0.3inWhen opening the hole, please adjust it according to the hardness of the wood. If the wood is soft, you can choose the smaller one. If the wood is hard, you can choose the corresponding or the larger one. The wood chips will be automatically discharged from the holes on both sides of the drill. , The design of the drill bit will not be stuck, and the perfect punching effect.Package List:8 x Hole Opener1 x Hex Wrench8 x Drill