Fork toe is also known as lost wax casting. Generally, it paints refractory on the surface of wax pattern, and then after hardening and drying the refractory, smelt out the wax pattern in it to make a shell. Finally, castings are gained through roasting and pouring the shell. As the castings gained by this method have high dimensional precision and smooth finish, investment casting can also be called as precision investment casting.
 
The rapid development of investment casting technology depends on its numerous advantages which mainly include the following aspects:
 
1. Investment Stem cam have high dimensional precision and small surface roughness.
 
2. It is able to cast thin-wall and light castings.
 
3. It can produce castings with fine designs, words, grooves and bending pores.
 
4. It is also capable to produce castings with complicated shapes which are difficult to manufacture for other processing methods like sand mould casting, forging and pressuring and cutting.
 
5. It can produce various kinds of alloy castings. Moreover, it decreases cutting and reduces material consumption.
 
6. Investment castings apply the shell with high strength and smooth surface as the mold cavity to directly contact with liquid metal. Therefore, sand drop is not easy to happen on them, and then it's good for them to ensure their inner quality.
 
7. The mould of precision AL shell moulding has low cost and long service life.
 
However, everything has pros and cons at the same time. There still some disadvantages that exist on the investment casting. They mainly include:
 
1. Investment casting has complicated processes and numerous procedures. Many factors affect the quality of castings. Thus, only through strict control of each material and processing operation, can castings be produced stably.
 
2. Castings are better to be not so large so as to avoid affecting dimensional precision.
 
3. The production cycle of investment casting is quite long.
 
4. The cooling speed of castings is so slow that it's easy to cause coarse grains of castings. Moreover, carbon steel castings are easy to form surface delamination.
 
However, disadvantages of investment casting are continuously improving with the development of its technology. Since the late 1940s, the application of multilayer shell has shorted production cycle and reduced material consumption and production cost. Moreover, the adoption of ceramic core and soluble core is beneficial to make the shape of investment castings better avoid limitations.
 
After passing through the evolution, investment casting becomes promising. Under the product of diligence and wisdom, investment casting will have more and more wide applications and get recognized by more industries. Not only that, it has get new breakthrough in lowering production cost and stepping up production. All of these enable the application of castings to be expanded so as to make them occupy a prim position in other industrial arts contests.