The NordLock® bolt securing system uses geometry to safely lock bolted joints in the most critical applications. This unique wedge-locking system offers the following advantages: - Maximum safety - Resists loosening caused by vibration and dynamic loads - Ease of assembly and disassembly - Locking function is not affected by lubrication - Positive locking at low and high preload levels - Controllable preload - Same temperature characteristics as standard bolt/nut - Reusable Nord-Lock® washers with enlarged outer diameter (sp) in combination with flanged nuts/ bolts are recommended for use on large/long holes, painted surfaces or soft materials, e.g. aluminium. The key is the difference in angles. Since the cam angle " a " is larger than the thread pitch " ß ", the pair of washers expand more than the corresponding pitch of the thread. NordLock® washers positively lock the fastener in a joint which is subjected to extreme vibration or dynamic loads.