Method and tool for clinching thick plates and use of the tool or of the clinching apparatus or of the clinching appliance

Clinching tool (20) for producing a load-bearing connection of a first metal workpiece (11) with a second metal workpiece (12), at least one of the workpieces having a thickness greater than 4 mm, wherein the connection does not include a perforation of either of the workpieces, wherein the clinching tool (20) comprises a die tool and a counter-tool (30) which together form, by deformation of the two metal workpieces (11, 12) without perforation, a clinch connection (13) connecting together the first metal workpiece (11) and the second metal workpiece (12), and wherein the die tool comprises a die (21, 22), which is constructed to be rotationally symmetrical with respect to a rotational axis (24) of the die and has a flank (25) arranged concentrically with respect to the rotational axis and a front end surface (23) lying perpendicularly to the rotational axis (24), wherein the flank (25) of the die is conically shaped at least in a lower region (21) to the front end surface (23) and has a varying flank angle (W, W1, W2) which is smaller than or equal to 10 degrees, characterized in that the flank angle (W, W1, W2) has a first angle portion (W1) extending along a length of the flank leading to the front end surface of the lower region (21), and a second angle portion (W2) extending along a length of the flank of an upper region (22), wherein the first angle (W1) is larger than the second angle (W2), wherein the upper region is adapted to at least partially sink into the metal workpieces during workpiece deformation without the die perforating either workpiece, and abutting ends of the first and second angle portions merge into each other without a step therebetween.