Using Belleville Springs To Maintain Bolt Preload

Live loading a joint by using Belleville Springs can improve retained preloading, increasing the elasticity of the fastening system by 900% or more. A properly designed live loaded system will decrease the probability of a joint failure by ensuring that minimum preload is maintained over time.

The theory of Belleville Springs is described here through the use of joint diagrams. Several tests were conducted to demonstrate the difference between an ordinary and a live loaded joint.