Tenon Cutters are the tools that cuts tenons on the end of your log rails and spindles. For log stair rails, use the 2" size Tenon Cutter. Northwest Tenon Cutters require the use of 1/2" or 3/4" drill, depending on size of cutter. Two high carbon steel blades flares the log end about 60 degrees. The two smallest sized Tenon Cutters have 1/2" shafts; the other sizes have 3/4" shafts. Use a 3/4" electric drill to power the 1½", 2", and 2½" tenon cutters because the drill should have a maximum of 500 RPM for both safety and limiting tool overload. Cast aluminum. Made in the USA.
Northwest Tenon Cutter Operating instructions 
Northwest Tenon Cutters have an adjustable shaft to allow custom sizing of the length of the tenons. See chart for maximum tenon lengths.