If you've struggled cutting fitting tenons, here's the perfect solution for you. CMT's tenon cutting router bit will produce perfectly fitting tenons in every board you cut, even if the boards vary slightly in thickness. Simply set the distance between the cutters using the included spacers, and you can easily cut tenons from 4,76mm (3/16”) to 9,5mm (3/8”) thick, up to 27mm (1-1/16”) long. This simple-to-use router bit takes the mystery out of achieving the excellent tenon-to-mortise fit required for high quality joinery. Safety precautions: maximum speed 12,000 RPM.