Practical design: - Designed with carbon steel, it has high hardness, wear resistance and high temperature resistance, and is durable. The sawdust is designed to be automatically discharged from the upper part of the holes on both sides, without clogging the drill. 7 sizes and 1 hex wrench: - 7 sizes of common center hinge bits 5/64'' 7/64'' 9/64'', 11/64'' 5mm, 13/64'', 1/4'' Great for drilling small hinges in cabinets, cabinets, furniture makers and other joinery or hardware items such as decorative boxes. Perfect connection and positioning: - There is no precise positioning and movement of this hinged center drill. Fits like butter and pores are smooth and full. Easy to install and safe to stop: - Easy to use and install, quick bit replacement, essential for assembly and disassembly for private and professional use. WIDE APPLICATIONS: - Drilled hinges with precise center holes are suitable for installing door hinges, pulls, drawer slides, etc. A must have for all home and area improvement enthusiasts.