The clamping shank (1) of a chisel-cutting and/or percussion boring tool bits has stop faces effective in the axial direction and in the circumferential direction. Entrainment faces (2), open towards a free end of the clamping shank (1) are located upstream of these stop faces in the direction of the cutting area of the tool bits. The radial dimension (r) of the essentially radially extending entrainment faces (2) is greater than their axial dimension (a). In cooperation with an appropriately designed tool bit receptacle, the entrainment faces (2) can carry such a large share of the torque, that the stop faces are effectively relieved or unloaded.