Specifications: Drilling diameter: 70mm Shank dimension: 9.7mm Overall length: 80mm. Applications: Can be used for drilling holes on plastic and wooden articles, furniture and door hinges. Used for cutting wood, plywood, solid wood boards, MDF, plastics and fiberglass, etc. Features: Tungsten carbide cutting tip with special heat treatment for sharp cutting edge, high hardness, no burrs and durable use. Arc curved head design for easy chip removal and more efficient perforation How to use: For bench drill, vertical drill, hand-held electric drill, impact drill, CNC cutting machine and other drill press. Processing hard materials such as Hardwood needs water injection to improve the accuracy and quality of drilling and to extend the service life of the hole opener. Warm tips: Can not drill metal and non-ferrous metal, otherwise the hole opener will be damaged quickly. Before drilling, make sure there are no nails or other metal objects in the wood to avoid damage to the drill bits. The