For stainless steel pipes for food and medicine, the content of harmful elements they contain must be within a range lower than the national standard. Harmful elements mainly refer to sulfur, phosphorus, lead, hexavalent chromium, etc. Surface treatment is not a means of distinction but only a process. High surface finish on both the inner and outer surfaces results in very little adhesion of media, which is beneficial for corrosion resistance. The higher the surface finish of the inner surface of the pipe, the less liquid medium will be retained, which is conducive to flushing. This is especially true in the pharmaceutical and food industries.