"ESDU 78043 presents data on the behaviour of initially flat or coned disc springs (Belleville washers) so that a spring can be designed to meet a required load/deflection characteristic. The condition of ""snap-through"" is covered. The data are given in non-dimensional graphical form and can therefore be applied to any size of spring in any elastic material. A comprehensive worked example illustrates the use of the information. ESDU 79010 and 80004 deal respectively with the design of nests of springs and with the fatigue life prediction of springs."