The NORD-LOCK Principles
Nord-Lock washers secure bolted joints with a tension instead of friction. The system is comprised of a pair of washers, supplied glued together, that have cams on one side and radial teeth on the other. The cam angle is greater than that of the bolt thread pitch, creating a wedge effect that prevents the bolt from rotating loose. Bolted Joints require two pairs of washers, one under the head and the one under the nut.