In life and work of people came into contact with a lot of equipment parts are by casting to and product's users are only interested in the quality of clearance of qualified products, and products quality a large part is casting of the decision process, thus casting knowledge is very important. The following is a description of a casting called: gravity casting, that is, the gravity of the liquid metal under the action of a process. It contains the type is also different, mainly to see you is from which point of view, such as the generalized angle, sand casting, metal mold casting, investment casting, lost foam casting, mud casting, etc. These are a kind of gravity casting; in essence, mainly is to pass the metal mold casting of a production method.