flexible exhaust pipe material: Q195,Q215,Q235,Q345,20#,30#,45# ... Square Stainless Steel Pipe,Stainless Steel Pipe,seamless stainless steel pipes,welded Stainless Steel Pipe and so on .flexible exhaust pipe: 1) Material: ... painted to prevent rust. 9) Application: square steel pipe can be used in construction structure machinery, container rall ... .We will do our best to help you. flexible exhaust pipe