Spektra Extreme Tool Life Coated solid carbide router bits are engineered with a nACo nanocomposite coating. This micro-thin ceramic coating enhances the cutting edge's sharpness and lubricity, ensuring that every cut is clean, smooth, and precise. The nACo coating not only extends the lifespan of the router bit but also provides heat resistance, allowing you to tackle even the most demanding materials. Spektra router bits maintain cutting performance under extreme conditions. The nACo coating prevents high heat which can degrade tool performance over time. With a hardness rating of approximately 4,500 Vickers, these bits have a solid hardness that is 2.5 times higher than uncoated bits. The multi-colored hues of the nACo coating will fade with use but rest assured that the coating's effectiveness remains intact. AMS-254-K 3-Pc: 46200-K Solid Carbide Spiral Plunge 1/8 Dia x 1/2 x 1/4 Inch Shank 46202-K Solid Carbide Spiral Plunge 1/4 Dia x 3/4 x 1/4 Inch Shank 45771-K Solid Carbide 30 Degree Engraving 0.005 Tip Width x 1/4 Inch Shank Signmaking Bit