Method and tool for precision cutting

A method for manufacturing a workpiece comprising a part configured to interlock with another part and having small corner radii in relation to a thickness to be cut and greatly reduced edge reduction by fine blanking in a fine blanking tool of a fine blanking machine, the method comprising:

• clamping the workpiece between two tool parts respectively consisting of an upper and a lower cutting die of the fine blanking tool, as well as of an upper cutting punch and a lower cutting punch of the fine blanking tool, wherein cutting is realized by combined efforts of said upper and lower cutting punches,
• cutting the workpiece in the fine blanking machine in at least two chronological cutting operations in different cutting directions without unclamping the workpiece between the two tool parts, said at least two chronological cutting operations comprising the following partial operations:
• (A) with one of said upper and lower punches, cutting out a semi-finished product corresponding to a first geometry of the workpiece by cutting along a first cutting line comprising the first geometry of the workpiece in a first vertical working direction, said cutting resulting in rollover at the first geometry of the workpiece, wherein the first geometry of the workpiece is an addendum circle;
• and
• (B) with another of said upper and lower punches, final cutting of the semi-finished product, fabricated according to operation (A), to cut material from the semi-finished product and thereby refine the first geometry, said final cutting comprising cutting along a plurality of second cutting lines each having an end at the first cutting line and the second cutting lines each being oriented relative to the first cutting line so that each of the second cutting lines together with the first cutting line forms a respective corner of the part configured to interlock with another part, the corner having a radius which is small in relation to the thickness of the material, and said second cutting being in a direction opposite the direction of the cutting in operation (A) and wherein the other of said upper and lower punches contacts portions of the semi-finished product comprising the rollover resulting from operation (A) thereby to ameliorate the rollover resulting from operation (A).