Abstract: A method for measuring the relationship between the angle of rotation of a threaded fastener and the torque applied to the threaded fastener and for detecting variations in the rate of increase of torque with respect to the corresponding angular displacement of the fastener within predetermined torque limits, the first torque limit being the lowest threshold torque that is experienced as the threaded fastener is tightened, the next higher torque limit being a calibrated starting point torque intermediate the lower torque limits for the zone of the desired maximum torque values for the fastener and the threshold torque, the next two higher torque limits defining the torque zone representing the desired maximum torque to be applied to the fastener to assure a quality assembly.