... pipe material: Q195,Q215,Q235,Q345,20#,30#,45# etc standard: GB/T6728-2002 or ASTM ... A500 We export main products include Square Stainless Steel Pipe,Stainless Steel Pipe,seamless stainless ... pipe: 1) Material: Q195,Q215,Q235,Q345,20#,30#,45# and so on . 2) Standard: GB/T6728-2002 or ASTM ... prevent rust. 9) Application: square steel pipe can be used in construction structure machinery, ...