[MATERIAL]: Our cutters are made of hardened steel. solid and made of C3 grain carbide. (C3 grade carbide is the highest grade used in the router bit industry). Precise product design creates smooth, detailed cuts that suit any all levels of complexity. [PERFECT DESIGN]: Hardened steel body; with anti-recoil design. Balance tolerance of +/- 0.003" (allowing smooth operation at very high RPMs). 3 C3 carbide tipped - Micro-grain grade provides superior ;maximum strength and toughness. [WIDE USE]: Router bit tools can cut most materials including: wood , MDF, particle board, plywood, board, soft wood, hard wood, etc. Suitable for handcrafted drawer or other woodworking, can be used to join wood from edge to edge or end to end.Perfect choice of professionals and hobbyists. [Where to use]：Designed for laptop or desktop wood engraving machines, such as handheld and table-mounted routers with bare control metric by computer. Note: it cannot be used in drills and electric drills.