Loading... Please wait...O Flute, Upcut, Spiral Router Bits - (2 Flute) Solid Carbide - Vortex 5830. Cutting Edge Diameter 1/4 Cutting Edge Length 3/8 Shank Diameter 1/4 Overall Length 2 1/2. Developed for cutting harder plastics, such as acrylic, at faster feed rates with a smooth finish. Ideal for CNC applications. Choose upcut for upward chip removal or downcut for better part hold down.