Grade: 10#-45#, api j55-api p110, 10#, 20#, 45#, api j55, api k55, api l80, api n80, api p110 thickness: 2 - 200 mm section shape: section shape place of origin: jiangsu, china (mainland) secondary or not: non-secondary application: boiler pipe technique: erw certification: api surface treatment: black special pipe: emt pipe alloy or not: is alloy c %: 0.28~0.33 si %: 0.1~0.35 mn %: 0.40~0.60 cr %: 0.9~1.1 mo %: 0.15~0.25 annealing hardness: 235 factory area: 2, 000, 000©o employees: 13, 000: 13, 000 business year: since 2000 shape: square. Rectangular.Round: square. Rectangular.Round treatment: black special pipe: emt pipe alloy or not: is alloy c %: 0.28~0.33 si %: 0.1~0.35 mn %: 0.40~0.60 cr %: 0.9~1.1 mo %: 0.15~0.25 annealing hardness: 235 factory area: 2, 000, 000©o