Chains are parts and accessories in various types of agricultural machinery, and are also wearing parts. The quality of its products directly affects the product quality and performance of the whole machine. Due to the wide variety of chain specifications, the chain can not only meet a large number of general mechanical requirements, but it is also difficult or even irreplaceable for other transmission methods in meeting special needs. For example, the rice-wheat harvester, taking the feed harvester as an example, regardless of the PRO488, PRO588, PRO688 and other models, from harvesting to threshing to the completion of a series of functions of cutting grass, the chain has played a coordinated role in transmission and transportation. The machine selects 2 types of chains, one is the 415 series chain with dial finger, and the other uses the 33 series clamping conveyor chain. The machine uses a total of 15 chains and 12 specifications.