Abstract: There are disclosed alternative methods of and apparatus for use in forming a rectangular metal tube having openings in at least one side from a flat metal sheet which has generally laterally aligned slots in its opposite longitudinal edges of a size and shape to form the openings when opposite one another and which is bent into a shape having longitudinally extending, inwardly turned flanges along its longitudinally extending edges. The bent sheet is arranged with an intermediate, longitudinally extending mid-portion between a longitudinally extending die and one face of an elongate punch and with its slots on opposite lateral sides of rams of the press on the opposite face of the punch, the rams being of a size to fit within the openings, whereby the rans may be moved in a direction to force one side of the die against the strip in order to swing the sides of the sheet and the longitudinal edges of the flanges inwardly toward one another to cause the slots to form the openings on opposite sides of the rams.