... it is known for high quality and more competitive price! ASTM A53 GR.B Seamless Tube 1.WT:2-40mm 2 ... ) Application: pipes for usual structure and machines 3) Model No.: ASTM A106 grade A/B, API 5L, X52, X42, ST52, K55, STK490 ... according to customers' requirements. 5) Foreign standards implemented: DIN, JIS, ASTM (ASME),etcASTM A-106 and ASTM A-53 Grade BChemical composition, %, no moreCMnSiPSCr0 ...