Pipe fitting including tee, elbow, flange, etc. Industrial metal pipe fitting products has the characteristics of wide application in various fields of national economy, products mainly supply of petrochemical industry, natural gas, shipbuilding, electric power, pharmaceutical and other industries, especially in ocean engineering and emerging areas such as nuclear power space. There are many methods of pipe fittings processing, many also belongs to the catagory of mechanical machining, the most used processing method is stamping, forging, rolling, ballooning, tensile, bending, and composite processing method. Pipe fittings processing is the combination of machining and metal pressure processing.