Pulley, belonging to the disc hub parts, generally the relative size is relatively large, the manufacturing process is generally casting, forging. The general size of the larger design for the casting method, the material is generally cast iron (casting performance is better), rarely cast steel (steel casting performance is not good); the general size of the smaller, can be designed for forging, the material is steel. Pulley is mainly used for long-distance transmission of power occasions, such as small diesel engine power output, agricultural vehicles, tractors, automobiles, mining machinery, mechanical processing equipment, textile machinery, packaging machinery, lathes, forging beds, some small horsepower motorcycle power transmission, agricultural machinery power transmission, air compressor, reducer, reducer, generator, cotton gin and so on.