Forstner Drill Bit: Drilling diameter: 22mm / 0.87"; shank size: 7mm / 0.28"; drilling depth: 48mm / 1.89"; total length: 79mm / 3.11". Thickened carbide cutter and solid hardened steel body, round shank forstner bits for woodworking. Applications: Can be used for drilling holes on wood and plastic products, furniture, door hinge. Used on cutting wood, plywood, solid wood boards, MDF, plastics, fiberglass etc.. Forstner drill bit is for ordinary purpose Features: Tungsten carbide cutting tip with special heat treatment for sharp cutting edge, high hardness, non-burrs and durable use. Arc curve design head for easy chip-removal, more efficient perforation How To Use: Suitable for bench drill, vertical drilling machine, CNC carving machine. Processing hardwood or other hard materials should be injected with water to improve the quality and accuracy of drilling, and extend the life of the hole opener. Tips: Maximum speed: 2000rpm. Used on desktop (fixed) equipment, and can NOT be used on handheld power tools (such as hand drill or electric drill). Can not drill metal and non-ferrous metal. To avoid causing damage, be sure no nails or other metal objects in wood before drilling. The cutting edge and tip of the opener should be sharpened in time.