The specification and drawings disclose a method and apparatus for forming dish-shaped metal elements through the use of a combined fluid pressure and sheet tensioning process. The disclosed method is particularly intended for forming dish-shpaed sheet metal elements having a length substantially greater than their width and includes applying a longitudinal tension to the sheet while permitting the lateral edges to move toward one another substantially unconstrained while the fulid pressure acts to bow the sheet. The disclosed apparatus includes a flexible frame of generally eliptical shape which clamps to the edge of the sheet. The frame is arranged so that as the sheet bows outwardly, the lateral sides of the frame are pulled inwardly driving the ends of the frame apart.