Can not drill metal and non-ferrous metal. 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. To avoid causing damage, be sure no nails or other metal objects in wood before drilling. QUARKZMAN 21 mm Forstner Drill Bit x 1 Piece Tungsten Carbide Featured - 21 mm Forstner Drill Bit Carbide Wood Hole Saw Auger Opener ! Features - Forstner drill bit for drilling clean holes in soft and solid hardwood 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). Arc curve design head for easy chip-removal, more efficient perforation. For drilling partially overlapped flat bottom holes for easy mortising., 6., Forstner Bit for industrial purpose is characterized with high hardness and long life, and resulting in nice finishing on woody pieces after cutting., 7., Should be use with bench drill, vertical drilling machine, CNC carving machine. Used on cutting wood, plywood, solid wood boards, MDF, plastics, fiberglass etc., ., Forstner drill bit is for industrial purpose Package Contents - 20mm 21mm 22mm woodworking forstner drill bits, use with bench drills, vertical drill presses, CNC routers. Material - Heat-treated tungsten carbide tip, sharp cutting edge, no burrs, high hardness, impact resistance, smooth cutting, wear-resistant, durable and long service life Features: Tungsten carbide cutting tip welded by high frequency technology, sharp cutting edge, high hardness, wear resistance, non-burrs and durable use. Tungsten Carbide Forstner Bit Sourcingap Forstner Drill Bits 38, Tungsten Carbide Wood Hole Saw 21mm Carbide Forstner Bit For Woodworking Flat Bottom Holes
