Precision casting is refers to the use of fusible materials meltability model, on which the coated with several layers of special refractory coating, after drying and hardening type to form a whole shell, reoccupy steam or hot water from the melt in the shell model, and then put type shells in the sand, dry sand by filling in all round its modelling, finally will be cast into the furnace after high temperature roasting, cast type or shell after roasting, and are casting in pouring molten metal.  It is not only applicable to the various types, various kinds of alloy casting, and produce the casting dimension accuracy and surface quality higher than other casting methods, or even other casting method is difficult to cast the complex, high temperature resistant, not easy machining castings, all can use revestment precision casting wrought.Revestment precision casting products for precision, complex, close to the final shape, precision casting can not machining or rarely used directly, is a kind of advanced net-shape forming technology, is an excellent technique in foundry industry, its application is very extensive.