The quality of the lifting chain itself is defective or problematic: for example, the material of the heavy chain is brittle, the welding is not strong, the wear is serious, and so on are the reasons why the lifting chain is easy to break. Non-normal damage to the material, manufacturing quality problems: ring chain welding and heat treatment manufacturing quality is a separate cause of broken chain is an important reason. Due to manufacturing quality and material quality standards, resulting in a single chain chain in the use of brittle fracture or plastic deformation fracture occurred. Brittle fracture occurs in the weld interface or weld heat affected zone; plastic deformation fracture occurs in the straight section of the ring and the ring junction, where the greater shear stress. Mainly due to material, heat treatment problems. Linkage fell into the iron: prone to twisted chain, resulting in broken chain.