Single-end tenoning machines generally comprise a rotary cutter fixed in relation to the machine, and a bed for moving a workpiece past the cutter. Such machines have limited capacity as the backing piece has to be changed at the end of each cycle. Patent Specification GB No. 2,125,729A (Boardman) describes an end-forming machine in which a tenoning cutter is moved in a lateral direction to engage one end of each of two workpieces. After one end has been tenoned, a workpiece can be moved longitudinally to a position in which the cutter tenons the other end. The machine still has limited capacity.