Solid Carbide Spektra(TM) Extreme Tool Life Coated, Plastic Cutting, Spiral 'O' Flute CNC Router Bits with special unique carbide with nACoA(R) nanocomposite coating for longer lifetime in plastics and other materials.The nACo micro-thin ceramic coating provides extreme nanohardness and heat resistance to the router bit. With a brilliant distinctively-tinted coloring nACo provides additional improvements in four critical aspects of router tooling.nACo coating is an micro-thin ceramic coating which enables the tool's cutting edge to retain crucial sharpness and lubricity. This provides longevity and produces cutting results of the highest quality.Coatings prevents high heat and oxidation which is detrimental to cutting tool performance.Multi-colored hues, while attractive, will dissipate upon use and yet coating will remain fully effective.nACo offers approximately 4,500 Vickers for impressive solid hardness on cutting areas of the tool, for an increase up to 2.5 times compared to uncoated bits.