The main factors that affect spring failure can be divided into 3 categories: spring material, spring design, and spring manufacturing process.
Spring Material
The chemical composition and mechanical properties of different steel grades in spring steel have their own characteristics. Generally speaking, the manufacturing material of spring should have a high elastic limit, fatigue limit, impact toughness, and good heat treatment performance. Commonly used are carbon spring steel, alloy spring steel, stainless spring steel and copper alloy, nickel alloy, and rubber. The spring material should be selected reasonably and correctly according to the stress requirements, service life requirements, and working environment requirements of the spring. Generally, we divide the tensile strength Rm into three levels, that is, the standards are given according to high, medium, and low.

If we use low-strength spring materials to produce springs bearing high stress in production, it is easy to produce permanent deformation and fail. If high-strength spring materials are used to produce spring products that require high fatigue life, the possibility of brittle failure of the spring under high-stress conditions increases.

The higher the strength of the spring material, the greater the tendency of the material to brittle fracture. Therefore, the correct and reasonable selection of spring materials with moderate mechanical properties can not only make the spring workload excellent, but more importantly, it can have excellent working performance under high fatigue life. Therefore, spring failure is closely related to the spring material.

Spring Design
A spring with good fatigue life needs to be designed by many people and through the knowledge of many disciplines.

When designing a spring, you need to understand what is necessary for a good spring fatigue life. Many spring products will fail due to unreasonable design parameters, resulting in permanent deformation in the early stage of use.

Spring Manufacturing Process
The forming, stamping, and bending of the spring during the manufacturing process may cause certain damage to the spring material. Some of these damages are obvious and some are invisible, especially for tension springs, torsion springs, and other special-shaped springs.

The maximum stress of the spring is on the surface of the spring material, and the fatigue fracture of the spring often starts from a small surface defect on the surface of the spring material. Then, under the action of alternating load, it gradually transitions and expands, and after a certain stress cycle, it will lead to spring fatigue failure.


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