... 37, St 42, St 52, Q 235, Q 195, Q345, 27SiMn 30 inch seamless steel pipe 10#,20#,45#,16Mn, ASTM A106 Gr ... .B, ASTM A53 Gr.B, St 37, St 42, St 52, Q 235, ... . SpecificationsChina StandardSteel GradeStandardseamless steel tubesand pipesfor structural purposeGB/T8162-199910, 20, 35, 45, 40Mn2, 45Mn2, 27SiMn, 20Cr, 40Cr, 20CrMo, 35CrMo, 38CrMoA1, 50CrV, 30CrMnSiASTM ...