In this paper, stretch flange forming experiments were performed on the AA5182 and AA5754 Al-Mg sheet materials. A triple-action servo-hydraulic press, developed at the University of Waterloo, was used in the experiments. A z-flange tooling, which incorporates mating drawbeads on the main and backup punches, was employed. Drawbeads are used in commercial stretch flange operations to control or limit the rate of cutout expansion. Of interest in the current research are the flange formability and the damage development induced by the bending-unbending of the sheet as it passes through the drawbeads. Both AA5182 and AA5754 were tested with thickness of 1.6 mm. Further tests were performed using 1.0 mm AA5182 to examine the effect of thickness. To examine the effect of cutout size on the formability, cutout radii in the range 88 to 98 mm in increments of 2 mm were tested to failure.