flexible exhaust pipe material: Q195,Q215,Q235,Q345,20#,30#,45# etc ... steel pipes,welded Stainless Steel Pipe and so on .flexible exhaust pipe: 1) Material: Q195,Q215,Q235,Q345,20#,30#,45 ... A500 or EN10219.or other materials according to customer'schemical component. 3) Process method:cold rolled hot rolled welded seamless galvanized ... us .We will do our best to help you. flexible exhaust pipe