The low pressure die casting is to let the melted metal flow into the casting mold under a certain degree of pressure, and solidify the casting part with the pressure as well. The pressure is powered by the inert gas or compressed air inside the sealed crucible, pressure push the upper surface of the liquid metal, force the liquid flow through the lift tube and gating, fill into the casting mold. The pressure is about 20~60 kPa. After full solidification, de-pressure the gas, make the unsolidified metal by gravity going back to crucible. The final casting part can be fetched when the mold is opened.