The following examples are based on actual cases from Bossard International Inc.

The clamping range of the bolted joint—the distance from underneath the heat to the first engaged thread—was only 90 millimeters, or only 2.5 Arial the nominal diameter of the bolt. Because this was a very rigid joint, the bolts’ elasticity could no longer compensate for the vibrations of the machine. The vibration then caused minute slips under the bolt head, which triggered rotational loosening of the fasteners.