Uses the force of gravity, instead of high pressure means, to fill a permanent mould, or die, with molten material.
There are four major steps in the die casting process.
1/  First, the mould is heated and then sprayed with lubricant and closed. The lubricant both helps control the temperature of the die during manufacture and it also assists in the removal of the casting.
2/  Molten metal is then manually poured into the die, (although in some cases a machine can be used) and allowed to solidify.
3/  The die is then opened and the cast parts either removed by hand or in some cases ejector pins are used on the mechanized machines.
4/  Finally, the scrap, which includes the gate, runners, sprues and flash, must be separated from the casting(s). This can be done using a special trim die in a power press or hydraulic press. An older method is separating by hand or by sawing, separation of running system from finished parts must follow. This scrap is recycled by remelting it.
Approximately 15% of the metal used is wasted or lost due to a variety of factors.

Advantages

• Good dimensional accuracy
• Smooth cast surfaces
• Thinner walls can be cast as compared to sand
• 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 is higher than sand casting.

Disadvantages
High initial cost.
A large production volume is needed to make this an economical alternative to other      
processes