The shrimp waist elbow is a kind of pipe bend, the shrimp waist elbow is very common, the blanking manufacture is very simple, but the traditional method to the present industry large pipe diameter elbow is difficult to operate, and it is difficult to ensure the accuracy. The shrimp waist elbow is much less used than the elbow welded with the original pipe and the middle plate. The material of the shrimp waist elbow is usually made of high quality cast steel, stainless steel or alloy steel, which can make the elbow withstand high pressure in all kinds of high-pressure pipelines and can withstand the corrosion of the fluid in the pipeline. At present, in the common specifications of elbow production has been heat push method or other forming process to replace, but in some specifications of elbow production due to a small number of too thick or too thin wall, stamping forming elbow method is still in use.