Surface Treatment: Add lubricating oil after phosphoric acid treatment. Features: Belleville springs can also be called disc springs,are conically formed annular discs, which are loaded in the axial direction. It offers a well-developed solution to many engineering problems through a unique combination of high force in a small space.It can be used as a single disc or arranged in stacks. Application: Belleville springs are widely used in mechanical products, such as press machine, artillery, aircraft and other heavy machinery,it can also be used as compression springs for automobile and tractor.