Dish-shaped spring is named for its appearance like a bowl, referred to as disc spring, also known as diaphragm reed. It consists of outer diameter (OD), inner diameter (ID), thickness (t) and height (H). The disc spring was invented by Frenchman J.Belleville in 1866, when it was mainly used as a washer. It is also known as the Belleville Spring because it has been patented in the United States and France. China's disc spring research is mainly in the 1970s, after the 1980s began to have enterprises to produce disc spring, with China's reform and opening up, the introduction of imported equipment, the improvement and stability of raw material quality. High quality disc spring is more and more widely used.