workpiece is less than the material hardness of the tool or if the contacting force is very large as already described a flat plastic or metal surface can also be used instead of the contour fig4 shows a plan view of an example of the second tool 2 which does not have an adjustment device in this case the surface region a is primarily responsible for the quality of the shaping since due to the size of the surface region a or of the corresponding surface 11 of the tool a region of the workpiece which is to be shaped is not covered and thus not exposed to a force due to this absence of stress the workpiece can flow in this region in accordance with the force applied by the third tool and the desired corner can be formed furthermore the holding surface 5 which is shown by dashes extends frame like along the corner that is to be shaped and into the back region of the second tool 2 there being a distance between its free end sections the two end sections can however also be connected with one another fig5 shows a plan view of the second tool as in fig4 with the difference that the underside fig2 a is constructed flat and that the tool has an adjustment device 13.