Stainless Steel Pipe is a kind of hollow long round steel, which is widely used in industrial transmission pipelines and mechanical structural components such as petroleum, chemical industry, medical treatment, food, light industry, machinery and instruments, etc. In addition, when the bending and torsional strength are the same, the weight is light, so it is also widely used in the manufacture of mechanical parts and engineering structures. It is also commonly used as furniture, kitchenware, etc. The standard of stainless steel pipe, Brinell hardness is the most widely used. The hardness of the material is often expressed by indentation diameter, which is intuitive and convenient.