For some gear products that do not require high precision (such as chain gears), they are very suitable for precision casting processing. The processed products have good uniformity and can meet the requirements of use. The main feature is low production cost and high efficiency. However, molds must be made in the early stage of production, which takes a certain amount of time. For such products, if CNC precision machining is used, the accuracy may be higher and the surface effect better, but the corresponding cost is higher. If the use requirements can be met, using precision casting production is a very good choice.