Multiple instances of abnormal fracture of 60Si2CrVAT steel outer circular springs have occurred in actual conditions of a certain open-top truck. To identify the causes of the fractures, we conducted tests on the fractured samples, including chemical composition analysis of the raw material, non-metallic inclusions and low-magnification structure inspection, geometric dimension checks, flaw detection and appearance inspection, hardness testing, optical metallographic examination, scanning electron microscopy observations of the fracture surface, and energy dispersive spectroscopy analysis. The results indicate that the raw materials and geometric dimensions of the fractured samples of 60Si2CrVAT spring steel meet industry standards and technical requirements. There are two main reasons for the abnormal fracture of the springs: firstly, during the grinding process, a newly introduced water-cooled wet grinding process was used instead of the dry grinding method due to environmental considerations, which effectively resulted in secondary quenching during grinding, causing thermal burn and creating a hardened layer of quenched martensite on the grinding surface of the support ring. This led to significant surface residual stress, initiating and propagating cracks at this location. Secondly, insufficient tempering of the springs resulted in an abnormal tempered sorbite matrix with a small amount of retained martensite, leading to excessive hardness, reduced toughness, and increased brittleness, which accelerated crack propagation. When the cracks reached a certain depth, the cross-sectional area of the spring could no longer withstand external forces, leading to rapid propagation and eventual fracture of the spring.