... : ISO9001, API 5L Perennial: stainless steel plate, seamless steel pipe, thick wall steel pipe, round steel, square tube, rectangular tube.Products: pipe: (GB/T8162 ... pressure alloy pipe: (GB/T5310-2008) and a series of steel products.Material: 10#, 20#, 35#, 45#, 20G, 20Gr-50Gr ... , 10CrMo910, T91, 15CrMo, 35CrMo, 40CrMo and a series of steel material.The company in the long-term business with major ...