There are many ways of making spring, but the main forming part is cold forming and hot forming.
In spring in the cold forming process, the spring mainly made by oil material toughening, lead bath quenching tempering spring wire, cold drawn wire, etc., using this kind of material in the manufacturing process of spring generally do not need special heat treatment and only requires the stress relieving, adopted by the spring design work stress and material performance.Spring cold forming process is generally suitable for special-shaped spring with small line diameter or more complicated shape, such as line diameter less than 15mm, various kinds of snap, pull, twist spring, convex, concave and arc spring, etc.The cold forming process is simple and avoids the deformation and decarburization of heat treatment again.
In the spring hot forming process, the spring is mainly made of hot rolled materials, annealing materials, annealing cold drawing materials, etc. The production of spring with such materials requires heating quenching and tempering heat treatment. The design working stress of spring is related to the selected material and heat treatment process.Spring hot forming process is generally suitable for springs with larger diameter or simpler shape, such as all kinds of cylindrical or conical spring with diameter greater than 6mm.The hot forming process is characterized by the larger value-added effect of the product and the larger diameter of the production line of the spring.