The [1/4-inch core hex handle self centered hinge practice is made of High-quality materials for doors and windows, but can also be used for drilling aluminum, copper, stainless steel, and other metal door and window hinges. Perfect for drilling in hinges, hardware, or any time you need to accurately locate holes. The self centered drill tip of the is customized and can be opened more accurately with less eccentricity to help with correct and center seated hinges. Other: has a flat bottom. The universal 1/4inch HEX is designed for a wide range of applications. It must be a center flight hole in various sizes. The self centered Change Door drill bit set includes 9 bits and 1 HEX key. The bit models are 5/64inch, 7/64inch, 7/64inch, 9/64inch, 9/64inch, 11/64inch, 5MM, 13/64inch, 1/4inch. A complete set of custom matches, comprehensive, comprehensive, just in case. The brightly colored case is pleasant and easy to recognize. The drill bit has a unique design and careful production, making it a good choice for DIY enthusiasts and , whether for self use or as a gift. Before using it for the first time, make sure to tighten the center drill bit. When you open the hole, please make appropriate adjustments based on the hardness of the wood. If the wood is loose and soft, you can choose smaller wood. If the wood is difficult, you can choose corresponding or larger wood. Material: Metal colour: Multicolor Package Contents: 9 x Self Centering Drill Bit(5/64inch, 7/64inch, 7/64inch, 9/64inch, 9/64inch, 11/64inch, 5MM, 13/64inch, 1/4inch) 1 x wrench 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.