Abstract: A thread rolling monitoring system in which one or more signal generating devices is provided in the mounting system of the stationary die of a pair of thread rolling dies. A sensor develops a signal which is a function of the reaction forces in a direction substantially parallel to the axis of the workpiece being threaded. The signal provides a running indication of the match or mismatch of the dies, as well as other conditions of improper operation. The signal is used to control the operation of the machine and to separate improperly formed parts as they are produced.