Precision castings are metal formed objects obtained by various forging methods. By pouring, injection molding, suction molding, or other casting methods into a pre prepared mold, cooling and subsequent processing techniques such as polishing, an object with a certain shape, precision casting scale, and function is obtained. Castings have a long history of use. In ancient times, people used castings and some daily utensils. In modern times, castings were primarily used as raw materials for machine parts, and some fine castings can also be directly used as machine parts. Castings account for a large proportion of mechanical products, such as tractors, with castings accounting for about 50.70% of the total machine weight. In agricultural machinery, castings account for 40.70% of the total machine weight, while in machine tools, internal combustion engines, and other types of castings, up to 70.90%. Among various types of castings, precision machining parts are mainly used for machinery. There are many types of castings with messy shapes and large quantities, accounting for about 60% of the total output value of castings. Next are steel ingot molds for metallurgy, pipelines for engineering, and some things in daily life.

There are various classification methods for castings: machined parts are classified into cast steel parts, cast iron parts, cast copper parts, cast aluminum parts, cast magnesium parts, cast zinc parts, cast titanium parts, etc. according to the different metal materials used. And each type of casting can be further divided into different varieties according to its chemical composition or metallographic arrangement. Cast iron can be divided into gray cast iron, ductile iron, ductile iron, malleable iron, alloy cast iron, etc; According to different casting methods, castings can be divided into general sand castings, metal castings, die-casting parts, centrifugal castings, continuous casting parts, investment castings, ceramic castings, electric slag remelting castings, bimetallic castings, etc. Among them, general sand castings are commonly used, accounting for about 80% of the total casting output value, while non-ferrous metal castings such as aluminum, magnesium, and zinc are mostly die-casting parts.