3Pcs Spiral Flush Trim Router Bit Set ,1/4 Inch Shank , With Nano Coated ,For Professional Flush Trim Router Bit with Top Bearing: 1/4? Shank, 1? Cut Length. The two independent ball bearings with forced on steel collars at the tip of each bit ensures smooth cutting surface. INDUSTRIAL QUALITY UPCUT FLUSH TRIM ROUTER BIT: Made of solid VIRGIN carbide with NANO blue coated. And Nano Blue Coating with high hardness and heat resistance enables the tool's cutting edge to retain crucial sharpness and lubricity. This provides longevity and produces smooth cutting results. Up to 2.5X longer lifespan compared to uncoated CNC bits. The 1/4-Inch flush trim Router Bits apply to various wood: such as Plywood, OAK, MDF, and any hardwood working. The spiral router bit suit for CNC router and any plunge routers with 1/4" collet.