1. Springs are divided into three groups according to their working characteristics 　　 (1). Springs subjected to dynamic load (that is, the force is stretched and shrunk suddenly, many times), and when the spring is damaged, it will cause the entire mechanism to malfunction. For example, engine valve springs, friction clutch springs, electromagnetic brake springs, etc. 　　(2) Springs subject to static load or uniform load increase, such as springs for safety valves and

The choice of spring material should be determined according to factors such as the nature of the spring's load, the state of stress, the magnitude of the stress, the working temperature, the environmental medium, the service life, the requirements for conductive and magnetic conductivity, process performance, material sources and spring price. 　　 When determining the shape and size of the material section, the series of sizes specified by national standards and ministerial standards should be selected first, and materials with non-standard series specifications should be avoided as far as possible.

​The application of springs is extremely wide, and the uses of springs are very wide. They can be used to store energy, reduce vibration, and measure force. In electromechanical products, there are many types of springs. In order to ensure that the spring can work reliably, its material should meet the higher strength limit and yield limit. Therefore, the choice of spring material is very important!

​A spring is a mechanical part that uses elasticity to work. Generally made of spring steel. It is used to control the movement of parts, alleviate impact or vibration, store energy, measure the size of force, etc. It is widely used in machines and instruments. The types of springs are complex and diverse. According to the shape, there are mainly spiral springs, scroll springs, and leaf springs.

​Mould is the main process equipment for industrial production. The development of modern industrial products and the improvement of technology level depend to a large extent on the development level of the mold industry. In recent years, the improvement of automation has led to the rapid development of foreign molds. Similar to the situation of many manufacturing industries

​Spring blackening process Alkaline chemical oxidation treatment to blacken is to put the processed qualified spring into a solution containing concentrated alkali and heat it to obtain a thin and dense oxide film on the surface of the spring, which has an anti-corrosion effect.