Castings have excellent dimensional accuracy. Usually this depends on the casting material, the typical value is the initial 2.5 cm size error 0.1 mm, each increase of 1 cm error is increased by 0.002 mm. Compared with other foundry processes, its casting surface is smooth and the fillet radius is about 1-2.5 microns. Castings with a wall thickness of about 0.75 mm can be manufactured relative to the sand box or the permanent mold casting method. It can directly cast internal structure, such as silk sleeve, heating element, high-strength bearing surface. Other advantages include the ability to reduce or avoid secondary machining, production speed, casting tensile strength of up to 415 MPA, can be casting high mobility of metal.