The counterweight plate is a heavy object used to increase its own weight to maintain balance.

The predecessor of counterweight disc is counterweight. Its development speed is very fast, one of the important factors is the progress of product technology, which requires castings to have better mechanical and physical properties and good machinability; Another reason is that the development of machinery industry itself and other industries such as chemical industry and instruments has created favorable material conditions for the counterweight iron industry. For example, the development of detection means ensures the improvement and stability of casting quality and provides conditions for the development of counterweight iron theory; The invention of electron microscope helps people to go deep into the microscopic world of metal, explore the mystery of metal crystallization, study the theory of metal solidification and guide the production of counterweight iron. During this period, a large number of new counterweight iron and metal materials with superior performance and rich varieties have been developed, such as nodular cast iron, weldable malleable cast iron, ultra-low carbon stainless steel, aluminum copper, aluminum silicon, aluminum magnesium alloy, titanium-based and nickel-based alloys. A new process of inoculation treatment of gray cast iron was invented, which made the adaptability of castings more extensive.