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. <EOS>