Die casting is a highly mechanized casting process, with high production rates and close tolerances. It produces castings which are often net shaped rather than near net shape; that is, by careful design and good process engineering, components can be produced which require little or no subsequent operations before being put into services. How close one gets to this ideal depends to some extent on the designer. 

Die casting is a process in which molten metal is forced, at high pressure and high velocity, into a hardened steel die to make close tolerance, thin walled and complex shapes. Depending on casting sizes and the number of cavities, hundreds and even thousands of parts can be produced each hour.

Since the size of the casting may vary from parts for watches or instruments weighing only a few grams to automobile engines and transmission cases, the size of the die casting equipment varies widely. The machine consists of three parts:

The machines are often fitted with ancillary devices such as auto-ladles, automatic die lubrication and takeout arms or robots, for removing the castings. Castings may be air or water cooled before being automatically fed to a trimming press to remove runners and feeds. All the ancillary equipment is synchronized to provide a highly mechanized, automated, high speed production process with low labor involvement.