During the use of the chain, due to the load, there may be loosening problems between the outer chain plate and the pin, as well as the joint between the inner chain plate and the sleeve during use. If the chain plate is perforated, the length of the chain will increase. , Show the fault situation.Because the center of the chain pin at the center of the rivet is loose, the chain plate will fall, and the chain may also be loose after the center mark is cut, which eventually leads to a chain failure.