Welded Spiral Steel Pipe 1.grade:Q235,Q345,10#,20#,16Mn,L245, ... ,GB/T 3.OD:219-3000mm thickness:6-25mm Welded Spiral Steel Pipe 1. Material:Q235,Q345,10#,20#,16Mn,L245 ... . Also for chemical industry, building structure and pile driving, etc. Spiral Steel Pipe1.grade:Q235,Q345,10#,20#,16Mn,L245,X802 ...