A tool and method for processing plate-shaped workpieces, such as metal sheets. An upper tool and a lower tool are moved toward one another with a workpiece arranged in between. The upper tool carries a processing tool on a main body opposite a clamping shank. The lower tool has a main body and bearing surface for the workpiece with an opening in the bearing surface. The processing tool of the upper tool has a bending edge and the main body of the lower tool has a counterpart bending edge which is positioned in the opening of the bearing surface. The bearing surface being displaceable relative to the counterpart bending edge such that the counterpart bending edge projects from the opening in the bearing surface.