Die casting is a metal casting process characterized by the use of a mold cavity to apply high pressure to molten metal. Molds are usually machined from stronger alloys, a process somewhat similar to injection molding. Most die castings are iron-free, such as zinc, copper, aluminum, magnesium, lead, tin, and lead-tin alloys and their alloys.

Molten metal is forced from the casting chamber through one or more casting channels into the cavity of the permanent steel mold, where it forms and solidifies in the shape defined by the mold. These die casting molds consist of two halves so that the casting can be removed from the mold.

Depending on the type of die casting, a cold chamber die casting machine or a hot chamber die casting machine is required. The main difference is that in a hot chamber casting machine, the vessel containing the molten metal is located inside the machine, while in the other case the vessel is located outside the machine. Casting equipment and molds are expensive, so the die-casting process is generally only used for mass-produced products. Manufacturing die-cast components is relatively easy, generally requiring only four major steps, with very low incremental cost per item.

Die casting is especially suitable for the manufacture of a large number of small and medium-sized castings, so die casting is the most widely used of various casting processes. Compared with other casting techniques, die casting has a flatter surface and higher dimensional consistency. The tensile strength of these materials is nearly double that of ordinary cast alloys, which has more positive significance for aluminum alloy automobile wheels, frames and other parts that are expected to be produced with higher-strength impact-resistant materials.