Brass is an alloy of copper and zinc. The simplest brass is a copper-zinc binary alloy, called simple brass or plain brass. Change the brass content of zinc can get different mechanical properties of brass. The higher the zinc content in the brass, the higher the strength, the plasticity is slightly lower. In the brass milling industrial, usually the brass and zinc content isn’t more than 45%, high zinc content will produce brittle, so that the deterioration of alloy performance. In order to improve the performance of brass, in addition to a single brass by adding other alloying elements of brass called special brass. Commonly used alloy elements are silicon, aluminum, tin, lead, manganese, iron and nickel. Alcohol in brass can improve the yield strength and corrosion resistance of brass, slightly lower plasticity. Brass with less than 4% aluminum has good processing, casting and other comprehensive performance. The addition of 1% tin to brass can significantly improve the ability of brass to resist seawater and ocean atmospheric corrosion, hence the "navy brass". Tin also improves brass cutting performance. The main purpose of brass plus lead is to improve the machinability and improve abrasion resistance, and lead has little effect on the strength of brass. Manganese brass has good mechanical properties, thermal stability and corrosion resistance; in the manganese brass aluminum, but also can improve its performance, get smooth surface castings. Brass can be divided into casting and pressure processing two types of products.