THE BEST QUALITY! THE BEST PRICE! THE BEST FACTORY! Standard:JIS, AISI, ASTM, ... ,310S,2205,2507.Type:WeldedSteel Grade:300 SeriesApplication:such as oil&gas,petrochemical,pulp&paper,electronicWelding Line Type:ERWThickness:0.5mm ... :polishingStainless steel tube for boiler:solution annealing steel square tube(high quality)