Understanding die casting fundamentals will aid product designers in making design decisions early in the product development process that can have the maximum effect on cost reduction and performance improvement.

Die casting technology has been advancing rapidly during the past twenty years, particularly in the last decade. Some die casters are adopting the newest technology, while others are not. There is, therefore, a wide diversity of die casting practice.

Die casting is a process in which molten metal is injected at controlled high velocity and pressure into the cavity of a mold (die) made of high quality steel. Rapid fill and high metal pressures, typically 2 to 10 ksi (14 to 69 MPa), give the process distinct characteristics. Rapid fill allows the temperature of the die to be maintained at a level 300F to 50F below the solidification temperature (solidus point) of the incoming metal in order to freeze (solidify) the casting as quickly as possible. Fill times may be as brief as a few milliseconds for the smallest components and as long as half a second for the largest. The high pressure imposed on the metal ensures complete cavity filling and faithful reproduction of intricate details.

Die castings also exhibit excellent surface quality and close dimensional tolerances, so that few, if any machining operations are necessary. These characteristics make the die casting process particularly well suited for components requiring high production volumes, intricate details and/or close tolerances.