Premium Carbide Cutters --- Featured with double flutes, straight shank, Solid hardened steel bodies with Anti-Kickback Design, Use on CNC and other automatic table-mounted portable routers. perfect for woodworking, edging, trimming, grooving, veining wood projects. Keep Sharp --- Premium C3 micro-grain tungsten carbide blades for a sharper & longer lasting edge. The carbide cutter ideal for create rail and stile cabinet door frames. Durable Carbon Steel Body --- Boasting alloy blade, fine craftsmanship and a solid hardened steel board these woodworking tools can withstand some heavy duty use and the test of time. Safety Use --- They feature 1/4" shanks which can provide greater stability and less vibration during use, safety and reliable to use. Wide Application --- These tongue and groove router bit set is truly versatile for your extra convenience. Works great with all kinds of materials and surfaces, like woods, mdf, particle boards, plywood, panels, softwood, hardwood and many others. However, please avoid to cut ferrous metal and non wood materials, such as steel, iron and sand.