Steel Spiral Welded Pipe 1.grade:Q235,Q345,10#,20#,16Mn,L245, ... :API,GB/T 3.OD:219-3000mm thickness:6-25mm Steel Spiral Welded Pipe1. Material:Q235,Q345,10#,20#,16Mn,L245,L290 ... appreciated!Spiral Steel Pipe1.grade:Q235,Q345,10#,20#,16Mn,L245,X802.standards:API,GB/T3.OD:219-3000mm thickness:6-25mm Steel Spiral ...