... tubes widely used in auto components, petroleum exploitation, pipe line, hear-exchanger & boiler, chemical machinery,farm e Main ... TubeBearing Steel TubeHydraulic Cylinder TubeSpecifications:A 53/A 53M Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, ... FieldsThe tubes widely used in auto components, petroleum exploitation, pipe line, hear-exchanger & boiler, chemical machinery,farm equipment, ship ...