... the process of the steel pipe ,so achieve consensus in metallurgical structure and mechanical properties, then after 100% hydrostatic test pressure ... , DIN, ASTMStandard: BS 1387, BS EN10296, GB 3087-1999, GB...Grade: 10#-45#, Cr-Mo alloy, 16Mn, A53-A369, AP ... ...Grade: 10#, 20#, 45#, 15CrMo, 16Mn, A53(A,B), A...Thickness: ...