... :painting,BE,plastic caps,ma ASTM A53 GR.B Seamless TubeSpecifications1)Seamless steel tube per ASTM A106B/ ... API-5L GR.B/A53 2)Size: 1/4"-28"*SCH20\30 ... for usual structure and machines 3) Model No.: ASTM A106 grade A/B, API 5L, X52, X42, ST52, K55, STK490, ... JIS, ASTM (ASME),etcASTM A-106 and ASTM A-53 Grade BChemical composition, %, no moreCMnSiPSCr0.17- 0.240.35- ...