welded steel pipe Grade: 304.321.316L.309S.310S O.D:3mm-12mm ... .0.25-1.5mm Appliance:Electronics,hardware,thermostats ect welded steel pipe Features: 1) Production Standard :ASTM A269;ASTM A554,2) ... Material of commonly used stainless steel:TP304,TP321,TP316L,TP309S,TP310;Material of other stainless ... hardness:high,middle,low.8),cuting without burr. Capillary welded steel pipe