carbon steel pipe material: Q195,Q215,Q235,Q345,20#,30#,45# ... steel pipes,welded Stainless Steel Pipe and so on .carbon steel pipe: 1) Material: Q195,Q215,Q235,Q345,20#,30 ... #,45# and so on . 2) Standard: GB/T6728 ... structure machinery, container rall structure, airport structure , shipbuilding and so on . 10) Packing: in bundles or bulk ...