It's widely known that steel ball usage generally has a long lifespan. However, some customers inquire about why steel balls purchased elsewhere may develop cracks. To address such issues, it's crucial to first understand the term "internal stress."

To consistently obtain high-quality steel balls, generally speaking, during the production process, steel ball factories do not need to undergo heat treatment for certain materials such as 3-series stainless steel balls (304, 316), but materials like bearing steel, stainless steel 440C, and carbon steel balls all require heat treatment.

Explanation of Steel Ball Cracking Causes

Heat treatment involves heating, holding, and cooling metal materials within a certain medium to alter the microstructure of the surface or interior, thus controlling their properties—a metal thermal processing technique. Post-heat treatment, residual stresses are present, and if internal stresses are significant, they can affect the internal structure of steel balls, leading to cracking during subsequent processing or in the application of finished products. Therefore, it is generally necessary to undergo strengthening after heat treatment. Strengthening entails gradually dissipating internal stresses and optimizing the internal structure of the steel balls, ensuring that the cracking issues mentioned above do not occur.

After the above description, it's clear how ball bearings can crack or develop fissures. The cause of ball bearing cracks or fissures still lies in the excessive internal stress after the heat treatment of the ball bearing, which affects its internal structure, leading to cracking or fissuring during subsequent processing and use.