Precision casting is a casting method compared with traditional casting technology.It can obtain relatively accurate shape and high casting precision.Common practice is: first make the required blank (allowance is very small or no allowance) of the electrode, and then use the electrode corrosion mold concrete, forming a cavity.The original wax mold was obtained by casting the wax again.Brush the wax mold layer by layer with high temperature resistant liquid sand.When sufficient thickness is obtained, it is dried and heated to melt the internal wax mold and obtain the cavity consistent with the required blank.Then molten iron is poured into the cavity, which solidifies and then the shell is peeled away to create a precision finished product.

Loss of wax method casting is now called investment casting, is a little cutting or no cutting casting process, is an excellent technology in the casting industry, its application is very wide.It is not only suitable for casting of various types and alloys, but also produces castings with higher dimensional accuracy and surface quality than other casting methods, and even complex, high-temperature resistant and non-easy to process castings that are difficult to be cast by other casting methods.

It was in the 1940s that the modern investment casting method was applied in industrial production.The development of aero-jet engines at that time required the manufacture of heat-resistant alloy parts with complex shapes, precise sizes and smooth surfaces, such as blades, impellers and nozzles.Due to heat resistant alloy materials difficult to machining, complex shape parts, so that can't or difficult to use other methods, therefore, need to find a new precision forming technology, then draw lessons from the ancient tradition of lost wax casting, after improvement of materials and technology, modern investment casting method on the basis of ancient technology for the development of the important.Therefore, the development of aviation industry has promoted the application of investment casting, and the continuous improvement and improvement of investment casting has also created favorable conditions for the aviation industry to further improve the performance.

China began to use investment casting in industrial production in the 1950s and 1960s. Since then, this advanced casting technology has been greatly developed, and has been widely used in the manufacturing industry of aviation, automobile, machine tool, ship, internal combustion engine, steam turbine, telecommunication instrument, weapon, medical apparatus and tools, as well as in the manufacturing of arts and crafts.

Another advantage of the investment casting method is that it can cast complex castings of various alloys, especially high-temperature alloy castings. For example, the blade of jet engine, its streamline profile and cooling with the cavity, with the mechanical processing process almost impossible to form. The production by investment casting process can not only achieve batch production and ensure the consistency of casting, but also avoid the stress concentration of the residual blade after machining.

The sprue cup is a basic part of the casting technology, especially in relation to the development of iron and steel industry. The runner cup is one of the components of smelting equipment.

The gate cup is mainly used to guide the liquid metal into the cavity. If the runner cups are not arranged properly, the castings may have defects such as air holes, trachomas, iron beans, slag holes, shrinkage holes, cracks and underpouring. Therefore, it is very important to choose the right structure and size of the sprue cup and place it on the casting.