die-casting, process by which molten metal is forced by a plunger or compressed air into a metallic die and the pressure maintained until the metal has solidified. Die castings are accurate, are sharply outlined, have a good surface finish, and can be made in complicated designs. Zinc, aluminum, and magnesium alloys are the principal metals used. The high cost of the die usually limits the process to large-scale, high-speed production. Typical products are carburetor bodies and zippers. Type-casting machines are specialized die-casting machines.