Pipe is necessary raw materials for pipe fittings, but there are many methods for pipe processing, as long as it is a method of machining, it can be applied. Pipe fittings is growing so rapidly in a foreign country. There are two prominent advantages, the first is to replace some of the machining products, less weight than machining, castings, forged structural parts, save material; the second is save processes, working hours than machining products, reduce workpiece cost.