TCT Carbide Tipped Knives offer over 1,000% (10 times) the tool life of M2-HSS. Carbide is used on hardwoods (i.e. Hickory, Hard Maple, MDF, plywood, etc.) Carbide is very hard (~92 Rc) and should be sharpened using a diamond wheel or silicon carbide type grinding wheel (call if you need these grinding wheels). Carbide can wear over 100,000 lineal feet, but is also brittle and can chip if the wood is not free of staples or rocks.