... 6-12.2m)No.Steel typeSteel gradeannual output/t1Oil casing Pipe, joint materialJ55,K55,N80-11000002Oil line pipeB,X42~X60(L245 ... /medium-pressure boiler tube10#,20#,A,B60005Transmission fluid tube10#,20#,Q295,Q345,Q390300006Structural use of seamless steel tubes10#~45#,40Mn2,35Cr,35CrMo500007Hydraulic ...