Upcut Finisher, Spiral Router Bits - (2 Flute) Solid Carbide - Vortex 1215. Cutting Edge Diameter 5/32 Cutting Edge Length 9/16 Shank Diameter 1/4 Overall Length 2. Two flute finishing tools are used when a smooth edge cut is required and is a popular tool design for most routing applications. The helical cutting edge reduces material contact while in the cut. This is why spiral tool designs cut faster, quieter, and cleaner than straight edge tools. These tools are used for cutting materials where no special considerations are needed. The upcut spiral will provide a smooth bottom finish, whileaugering the chips upward. Due to the upcut design and the included angle of the cutting edge, these tools are razor sharp!