Die casting is a metal casting process that is characterized by forcing molten metal under high pressure into a mold cavity. The mold cavity is created using two hardened tool steel dies which have been machined into shape and work similarly to an injection mold during the process. Most die castings are made from non-ferrous metals, specifically zinc, copper, aluminium, magnesium, lead, pewter, and tin-based alloys. Depending on the type of metal being cast, a hot- or cold-chamber machine is used. Advantages of die casting: Excellent dimensional accuracy (dependent on casting material, but typically 0.1 mm for the first 2.5 cm (0.004 inch for the first inch) and 0.02 mm for each additional centimeter (0.002 inch for each additional inch). Smooth cast surfaces (Ra 1–2.5 micrometres or 0.04–0.10 thou rms). Thinner walls can be cast as compared to sand and permanent mold casting (approximately 0.75 mm or 0.030 in). Inserts can be cast-in (such as threaded inserts, heating elements, and high strength bearing surfaces). Reduces or eliminates secondary machining operations. Rapid production rates. Casting tensile strength as high as 415 megapascals (60 ksi). Casting of low fluidity metals.