Precision casting is the general term for the process of obtaining precision-sized castings. Compared with the traditional sand casting process, the castings obtained by precision casting are more accurate in size and have a better surface finish. Precision casting is also known as lost wax casting. Its products are precise, complex and close to the final shape of the part. They can be used directly or machined to a polished and brushed surface. The casting process consists of the following five parts: wax injection, shell making, wax treatment, roasting and post-treatment.