Nord-Lock locking washers
Have a wedge-locking action which is a unique method using tension instead of friction. The rise of the cams between the Nord-Lock locking washers is greater than the pitch of the bolt. In addition, there are radial teeth on the opposite side. The locking washers are supplied and installed in pairs, cam face to cam face, and when the bolt and/or nut is tightened the teeth grip and seat on the mating surfaces. The washers are locked in place, allowing movement only across the face of the cams. Any attempt by the bolt/nut to rotate loose is blocked by the wedge effect of the cams, which positively locks the fastener even when it is subjected to vibration or dynamic loads.