Introduction Coned disk springs@ also known as Belleville Springs@ have a long history. In 1835@ one Timothy Hackworth@ in England@ received acknowledgment for an application in a safety valve. A Frenchman@ Julian F.Belleville@ secured a British patent in the 1860's for a particular application. AT that time@ these springs were mainly used in the buffer parts of railway rolling stock and for recoil mechanisms of guns@ etc. Whenever space is limited@ particularly in the presence of high forces@ the use of coned disk springs will be of advantage. Linear@ regressive@ and even progressive load-deflection characteristics can be obtained by varying the basic dimensions or by stacking. A large number of standard of-the-shelf sizes is available@ so that custom sizes may not be required. For these reasons@ coned disk springs are used today in virtually all branches of engineering with new applications surfacing all the time.