Material: High Carbon Steel, high quality alloy blade, make blade more sharp and durable. It's head adopt arc curve design, beneficial to chip removal, perforation is more efficient.High quality: Sharp edge, high hardness, accurate positioning, high precision, smooth cutting, impact resistance, high toughness. more smooth, less noise.Widely used: Can be used for wood products perforation, mounted spherical door shoot tip, drawer, plastic products, wood, plywood, etc.Suitable for pistol drill, bench drill, vertical drilling machine hand held electric drill, stand motor-driven drilling machine and mobile ribbon type magnetism drilling machine, etc.Include 5 different boring diameters: 15mm/20mm/25mm/30mm/35mm. A variety of sizes to provide a choice.Features:Processed by the painting, the cutter is water-proof, anti-corrosive, and durable.It is far safer and more accurate to use this drill bit in a drill press.In design with curve, the head is good at removing the debris and working efficiently.The tip is specially designed to cut through hole cleanly, great for boring concealed hinges and door clocks.It is suitable for cutting holes onto woods.Precision ground for heavy use and easily resharpened, they can enlarge existing holes with ease and can bore any arc of a circle.