Precision casting is a relatively economical method for blank forming, which can better demonstrate its economy for parts with complex shapes. Such as the cylinder block and cylinder head of car engines, ship propellers, and exquisite artworks. Some difficult to cut parts, such as nickel based alloy parts of gas turbines, cannot be formed without casting methods.

In addition, the size and weight of the cast parts have a wide range of adaptability, and the types of metals are almost unrestricted; Parts not only have general mechanical properties, but also comprehensive properties such as wear resistance, corrosion resistance, and shock absorption, which cannot be achieved by other metal forming methods such as forging, rolling, welding, and punching. Therefore, in the machine manufacturing industry, the number and tonnage of raw parts produced by casting methods are still the largest to date.

There are many types of casting, which are traditionally divided into:

1. Ordinary sand casting includes three types: wet sand mold, dry sand mold, and chemically hardened sand mold.

2. Special casting, According to the molding materials, it can be divided into two types of casting production: special casting with natural mineral sand and gravel as the main molding material (such as investment casting, mud casting, shell casting in casting workshops, negative pressure casting, full mold casting, ceramic mold casting, etc.) and special casting with metal as the main molding material (such as metal mold casting, pressure casting, continuous casting, low-pressure casting, centrifugal casting, etc.), which have different characteristics from other processes, Mainly due to its wide adaptability, high demand for materials and equipment, and environmental pollution. Casting production produces dust, harmful gases, and noise that pollute the environment more severely than other mechanical manufacturing processes, and measures need to be taken to control them.