Spetool Carbide Insert Surfacing Router Bit Spoilboard Planing 1-1/4 Inch 2+2 Inserts Design. 2 wings wood cnc router, 1/4? shank, 1-1/4? cutting diameter, 1/4? shank, use 10*10*2.2 carbide insert.the inserts will be available on asin "B09CPDVBSG , B0CGR7S8SR" Durable and Economical. The 4 edges of carbide inserts can be used with a screwdriver, 2.2mm thickness carbide provide longer life than other carbide blade. Replace the carbide inserts instead of entire bit when dull Extra-Long Life. With the ATS coated carbide, it provide a 2 times longer life than the no coated carbide insert Multi-Use. Used on soft and hard woods, particle board, MDF, plywood compact panel, laminate, acrylic and etc. Application Equipment. Perfect for wood slabs flattening, can be used on wood slab, hand router, cnc router