Developed for smaller diameter tenon cutting, for use with small stock. They are available in cutting diameters from 5/16" to 9/16". The 9/16" tenon is the size used historically for chair rungs. The 1/2" size is useful in many areas e.g. members within trellis or lattice work. All the sizes have a straight blade that cuts a 60° shoulder tenon (not a radiused shoulder tenon as on the larger sizes). The 5/16" cuts tenons up to 1" long, and the 1/2" and 9/16" cut tenons up to 1.3/8" long. A plug gauge is included for easy blade setting. 3/8" round shank. Patented. (For use in an electric drill, not a drill press).