What is the difference between 16Mn and Q345C seamless steel pipe?

16Mn and Q345C are two different grades of seamless steel pipe. 16Mn is the grade of the old GB standard, and 16Mn is called Q345B in the new GB standard.

The main difference between 16Mn and Q345C seamless steel pipe lies in their different mechanical properties. 16Mn (Q345B), where B refers to the impact temperature is 20℃, normal temperature impact. Q345C seamless steel pipe, C refers to 0℃ impact.