Permanent Mould Casting:

Although sand casting generated the bulk of the castings in modern industry, a big quantity of small size castings are cast through permanent mould casting. As metal is fed into the mould through gravitational force, also this procedure is referred as "gravity die casting". As die casting this procedure utilizes metal moulds and cores. In conventional die- casting molten metal is provided external pressure to fill up the mould cavity while, in this procedure no external pressure is needed to fill up the mould cavity. In contrast to the sand mould the permanent moulds are utilized repeatedly. The cores are utilized for producing hollow sections. Generally the simple detachable cores are made of metal, but more difficult cores where core elimination is not easy these are made of or plaster or sand. While sand or plaster is utilized as a core material the procedure is called as semi permanent mould casting. Permanent mould casting procedure is very useful for high volume production of castings along uniform wall thickness and restricted undercuts.