Bending tools for pre-bending and hemming

A bending tool set for v-shaped prebending and subsequent hemming of a flat workpiece section, the bending tool set comprising:

• (a) a working plane;
• (b) at least one bending punch with a constant punch thickness perpendicular to the working plane, wherein the at least one bending punch comprises a punch tip, a punch base surface, a punch section arranged centrally relative to the working plane and extending from the punch base surface, and a bending punch hemming section comprising a bending punch hemming surface arranged laterally to the punch base surface and projecting relative to the punch base surface toward the punch tip, wherein the bending punch hemming surface projects in a stepped manner relative to the punch base surface;
• (c) at least first and second bending dies;
• and
• (d) a groove-shaped recess formed between the punch section and the bending punch hemming surface;
• wherein the first and second bending dies comprise, respectively, first and second interiors, first and second die sections arranged centrally relative to the working plane and having, respectively, first and second bearing surfaces, first and second slots leading into the first and second interiors of the first and second bending dies, respectively, for partly receiving the at least one bending punch during a hemming operation, first and second bending die hemming sections comprising, respectively, first and second bending die hemming surfaces arranged laterally with respect to the working plane and set back in a stepped manner relative to the first and second bearing surfaces, respectively, and first and second stop surfaces extending from the first and second bearing surfaces to the first and second bending die hemming surfaces, respectively;
• and
• wherein each of the first and second bending dies on a respective inside of the first and second slots, respectively, has an identical internal support width corresponding to the punch thickness in addition to play and the first die section in a region of the first bearing surface has a first die width different from a second die width of the second die section in a region of the second bearing surface.