What is "bolt fatigue"?

Bolt fatigue refers specifically to the failure of a bolt after being subjected to numerous cycles of loading and unloading, which can lead to the development of micro-cracks within the material. Over time, these micro-cracks can propagate, ultimately resulting in the bolt's inability to withstand further stress, leading to its failure. This phenomenon is particularly critical in mechanical and structural engineering, where components experience fluctuating loads during their service life.

Understanding bolt fatigue is essential for engineers and designers because it highlights the importance of considering the cyclic loads that fasteners or structural components will encounter in their operating environment. This knowledge helps in selecting the appropriate materials and specifications to ensure the mechanical integrity and longevity of the assembly.