Up Cut 2 Flute 1/4inch Shank CNC Router bits Ball Nose End Mill with Nano Blue Coating Cutting Diameter: 1/4 inch for Side Milling,End Milling,Finish Machining T2130BC Industrial Solid Carbide CNC 2D and 3D Carving Tapered Ball Nose. NaCo Coated Router Bit allows you to achieve precision, depth, unparalleled accuracy, detail and clarity in foam and other modern-day materials. This ZRN coated end mill has a 1/4" cutting diameter x 1" cutting length. The overall length is 3" with a 1/4" shank. With the added coating, the bit's lifespan and durability are increased substantially avoiding unnecessary down time. These bits pull the wood chips up and away from the tool path which helps prevent tool breakage and extends the life of the bit.