Nord-Lock Inc.

This bolt securing system withstands the effects of vibration on applications where a bolt and nut might attempt to loosen.
A unique 2-part lockwasher that holds better than a locknut, nylon insert nut, or liquid threadlock; by using tension on the joint rather than friction.
Made of carbon or stainless steel, these washers range from #5 screw to 5 inch. Sold in pairs to many different manufacturers where safety is mandatory.
Nord-Lock is reusable, and is simply designed to maintain a tight joint in critical areas on various equipment, from wheelchair to ambulance to rock hammer. www.nord-lock.com