Reasons for breaking of double ring shackle of a crane chain

A double ring shackle of a crane chain broken during operation. Fracture morphology analysis, chemical composition analysis, metallographic examination and hardness test were used to analyze the fracture causes of the shackle, and the finite element analysis method was used to check the stress of the shackles with different diameters. The results show that the root cause of fracture was that the diameter of the shackle decreased due to excessive wear. Standard periodic inspection, timely replacement of excessive wear parts could avoid shackle fracture.