Abstract: The invention relates to a tool holding system for automatic tool changing in a machine tool, stamping machine or other such machine, wherein the machine has a spindle which has at its free end a gripping means in the form of a sleeve for a tool which can be inserted and removed by a tool changing system, while a draw rod actuating the sleeve by axial displacement is guided in the spindle, and the tool having at the spindle end a tool holding head with an inverted centering frustum cone which can be engaged by a conical inner surface of the sleeve in its clamping position in order to clamp the tool against the spindle.