The technology of powder metallurgy are applied in various industries such as office automation, electric motors, audio equipment, home appliances, industrial machine and transportation machine. The advantages of powder metallurgy is that it can copy high precison and compicate shape products by molding so that the efficiency of production is highly increased. Moreover, it reduce the waste of materials during machining so that the cost of production is reduced. Besides, different kinds of metal powder can be blended together to obtain different characteristic of products.