Tubes are specified that are suited to the respective nominal diameters of exhaust gas lines of internal combustion engines and steam boilers on ships. In two of three wall thickness series the tubes are taken from DIN 2448 and DIN 2458. The third series gives indications on outer diameter, wall thickness and material of tubes in the range of 200 to 3000 mm nominal diameter which are to be made of plates according to drawings.#,,#