... 5)API,ISO,CE,etc BG API carbon steel round head pipe TypeApplicationStandardMaterialalloy steel pipeit is used in ... tubeASTM A106ASTM A53A53 BA106 Bsteel pipe forstructureUsed in general structure,engineering scaffolds, mechanicalASTM A53A53 Bpipeline steel pipeUsed in oil ... ,X56,X60,X65,X70,X80ERW STEEL PIPEUsed in general structure stents, low voltage liquid transportation, etcGB/T13793-1992GB3091 ...