An arrangement for the force-locking connection of an adapter shaft to a shaft by means of a clamping ring, wherein the clamping ring is mounted on the adapter shaft, wherein the shaft is inserted into the adapter shaft, wherein the clamping ring has a first radially uninterrupted threaded bore into which is screwed a first screwing part, in particular first grub screw, which presses on the adapter shaft, wherein the clamping ring has a second radially uninterrupted threaded bore into which is screwed a second screwing part, in particular second grub screw, wherein the second screwing part at least partially extends into an indentation of the adapter shaft, in particular and presses on the adapter shaft, wherein the adapter shaft has axial slots, wherein the axial slots are spaced apart regularly from each other in the peripheral direction and/or the axial slots are radially uninterrupted and/or open out on a first axial end of the adapter shaft, in particular into the surroundings, wherein the axial slots are embodied to be open in relation to the axial end of the adapter shaft, in particular therefore open into the surroundings, in particular ambient air, characterised in that that surface region of the adapter shaft on which the first grub screw presses is embodied as a flattened portion, in particular as a flattened portion oriented tangentially to the adapter shaft, with the region covered by the indentation in the peripheral direction encompassing the region covered by a first one of the axial slots in the peripheral direction, and with the region covered by the indentation in the axial direction being encompassed by the region covered axial slot [sic] in the axial direction. wherein the clamping ring is mounted on the adapter shaft, wherein the shaft is inserted into the adapter shaft, wherein the clamping ring has a first radially uninterrupted threaded bore into which is screwed a first screwing part, in particular first grub screw, which presses on the adapter shaft, wherein the clamping ring has a second radially uninterrupted threaded bore into which is screwed a second screwing part, in particular second grub screw, wherein the second screwing part at least partially extends into an indentation of the adapter shaft, in particular and presses on the adapter shaft, wherein the adapter shaft has axial slots, wherein the axial slots are spaced apart regularly from each other in the peripheral direction and/or the axial slots are radially uninterrupted and/or open out on a first axial end of the adapter shaft, in particular into the surroundings, wherein the axial slots are embodied to be open in relation to the axial end of the adapter shaft, in particular therefore open into the surroundings, in particular ambient air, characterised in that that surface region of the adapter shaft on which the first grub screw presses is embodied as a flattened portion, in particular as a flattened portion oriented tangentially to the adapter shaft, with the region covered by the indentation in the peripheral direction encompassing the region covered by a first one of the axial slots in the peripheral direction, and with the region covered by the indentation in the axial direction being encompassed by the region covered axial slot [sic] in the axial direction.