... ,HL,200# polishing, 400 # polishing 316L stainless steel tube Stainless steel is a production which not easy rust,acid ... A 709,ASTMA302,ASTMA537,API X52,API X 42 and so on.specificationThickness:0.5mm-140mmProduction technologyHot rolledCold ... 180#,220#,240#,320#400#,600#), Hairline,aid pickling and so onProduction technologySeamless steel pipeWelded steel pipeSurface treatmentPolishing or ...