Casting has a variety of classification methods: According to the different metal materials used, divided into steel castings, cast iron, cast copper, cast aluminum, cast magnesium, cast zinc, cast titanium parts. And each type of castings can be further divided into different kinds according to their chemical composition or metallographic structure. such as iron castings can be divided into gray iron castings, ductile iron castings, vermicular graphite iron castings, malleable cast iron parts, alloy iron castings, etc. according to the different mold forming method, the castings can be divided into ordinary sand castings, metal castings, die castings, centrifugal castings, continuous casting parts, investment castings, ceramic castings, electroslag remelting casting parts, bimetal castings, etc. The common sand castings are used most, about 80% of the total casting output. and aluminum, magnesium, zinc and other non-ferrous metal castings, mostly die castings.