To make simple, fast work of mortise-and-tenon joinery, this system uses power tenon cutters and matching countersinks (sold separately) to produce strong flush-fitting joints in round or dimensioned stock. The cutters produce a symmetrical tenon with a 60° tapered shoulder that fits neatly in a countersunk socket. The main blade shapes the tenon and shoulder, while a finishing blade smoothes the tenon to a consistent diameter and cuts a slight relief at the base of the shoulder to ensure it seats flush. The finishing blade's cutting depth is adjustable, so you can fine-tune the tenon diameter for close fit.