Gravity die casting tends to be a much more manual process compared to other casting methods, relying on the force of gravity alone to achieve the required component shape. It is also capable of producing high-quality parts with less need for secondary machining operations; however, it may prove to be more expensive than the likes of sand casting, owing to the associated tooling costs.
Gravity die casting utilises a permanent mould - or die - typically made of metal, into which molten material is either ladled or poured. Although this process can be automated to assist with higher-volume production, it is usually performed by hand. Due to the force of gravity, the molten material settles in the cavity and hardens as it cools. To ensure that the material has settled into all areas of the cavity, the mould is sometimes tilted before the metal is allowed to cool, although this is generally the only interference that takes place.
Once the material has hardened, the die is opened and the components retrieved, ready for finish machining to take place. Gravity die casting results in an excellent surface finish with tight tolerances also achievable, which means that secondary operations are usually limited to removing sharp edges, as well as drilling any required holes, etc.
Gravity die casting is primarily used to produce components made of aluminium alloy, although steel, cast iron, magnesium, copper and zinc can also be used.