... seamless steel pipe, thick wall steel pipe, round steel, square tube, rectangular tube.Products: pipe: (GB/T8162-2008): (GB/T8163-2008 ... -2008), high pressure boiler tube: (GB/T5310-2008), oil cracking tube: (GB/T9948-2006), hydraulic prop tube: (GB/T17396-1998), ... fertilizer dedicated tube: (GB/T6479-2000), ...