无缝钢管知识大全??1.一般用途无缝钢管ASTM A53 GR.B,钢号:SA53 B,规格:1/4″-28″,13.7-711.2mm ??2.高温作业用无缝钢管ASTM A106 GR.B,钢号:SA106B,规格:1/4″-28″,13.7-711.2mm ??3.管线管API SPEC 5L,钢号:B、X42、X46、X52,规格:1/4″-28″,13.7-711.2mm ??4