preferably the same as the diameter of a deepest portion of the recess channel 54 the first die element 60 has an axial height 61 which is the same as the axial height of the die head 36 and surrounds both the first axial portion 66 and the second axial portion 68 of second die element 62 in the radial direction in this embodiment the outer circumference of the die head 36 is formed exclusively by the first die element 60 the first die element 60 has a greater radial thickness in the region of the second axial portion 68 than in the region of the first axial portion 66 a parting seam 74 between the first die element 60 and the second die element 62 runs from the deepest region of the recess channel 54 initially in the form of a cylindrical surface as far as the first axial portion 66 in this region the parting seam 74 comprises a radially oriented annular surface which is oriented parallel to the bearing surface 44 proceeding from this radially oriented annular surface the parting seam 74 furthermore has a second cylindrical surface which is formed in the region of the first axial portion 66 and the diameter of which is the same as the first diameter 70 of the first axial portion 66 the parting seam 74 is represented here by surfaces which are oriented substantially at right angles to one another however the parting seam 74 can also be formed by a purely axial cylindrical surface or at least in certain portions by oblique in particular conical surfaces the first die element 60 is produced from a first material for example a tool steel which has a greater ductility than the second material likewise for example a tool steel of.