Tornado Compression, Spiral Router Bits - (4 Flute) Left Hand, Solid Carbide - Vortex 3580L. Cutting Edge Diameter 3/4 Cutting Edge Length 2 Shank Diameter 3/4 Overall Length 4. Another Industry First! The Vortex Tornado roughing/finishing tool is the fastest cutting router bit in the world! If you have the machine to do it, we've got the tool. With increased feed speeds (as much as 3500 IPM) this tool will provide a clean cut on double sided materials such as melamine and formica laminated particle board.