This part of prEN 1592 specifies the tolerances on dimensions and form of circular HF seam welded tubes with a diameter up to and including 80 mm and a wall thickness up to and including 2,5 mm. These tubes are manufactured from flat rolled aluminium alloy strip longitudinally welded in a continuous process by the passage of an electric current across the abutting edges without the addition of filler metal. This standard also applies to tubes manufactured from aluminium alloy strip which is painted, lacquered or anodized prior to forming.