Abstract: A device for measuring at least one force component during cutting operations on workpieces with machine tools, including a dynamometer with measuring elements, integrated in a base module of a modular toolholder so that it is directly engaged with the cutting tool. The base module may be combined with various clamping and mounting modules to allow adaptation to standardized clamping systems of different machine tools, and to standard tools. The integration of the dynamometer in the toolholder and the direct engagement between cutting tool and dynamometer gives a compact unit with only small or no force shunts, making possible precision measurements. The device is therefore suitable for, among other duties, calibrating existing monitoring sensors of machine tools and for comparative functional tests on different machine tools. Measuring and evaluation electronics may be integrated in the device, wholly or in part.