A clamping connection having - a hollow shaft portion, - a shaft at least partially inserted into the hollow shaft portion, - a screw, in particular a clamping screw, and - a clamping ring, wherein the screw has a screw thread and a screw head which rests against a plane bearing surface of the clamping ring, which screw head has a largest diameter which is larger than the largest diameter of the screw thread, wherein the hollow shaft portion has a flattened portion, therefore a region with reduced radial wall thickness compared with the radial wall thickness outside of the region and/or with reduced outer radius compared with the wall thickness outside of the region, wherein the screw, in particular with its screw thread, at least partially rests against the flattened portion, wherein the screw is spaced apart from the shaft, in particular from the outer surface of the shaft, characterized in that the hollow shaft portion has an axial slot, in particular an axial slot passing radially through the hollow shaft portion, and the axial course of the greatest radial spacing of the clamping ring has a constant region adjoined at both sides by a respective rounded region, in particular a circular portion, at whose side remote from the constant region there adjoins a respective linear region in which there runs the greatest radial spacing proportional to the axial position. - a hollow shaft portion, - a shaft at least partially inserted into the hollow shaft portion, - a screw, in particular a clamping screw, and - a clamping ring, wherein the screw has a screw thread and a screw head which rests against a plane bearing surface of the clamping ring, which screw head has a largest diameter which is larger than the largest diameter of the screw thread, wherein the hollow shaft portion has a flattened portion, therefore a region with reduced radial wall thickness compared with the radial wall thickness outside of the region and/or with reduced outer radius compared with the wall thickness outside of the region, wherein the screw, in particular with its screw thread, at least partially rests against the flattened portion, wherein the screw is spaced apart from the shaft, in particular from the outer surface of the shaft, characterized in that the hollow shaft portion has an axial slot, in particular an axial slot passing radially through the hollow shaft portion, and the axial course of the greatest radial spacing of the clamping ring has a constant region adjoined at both sides by a respective rounded region, in particular a circular portion, at whose side remote from the constant region there adjoins a respective linear region in which there runs the greatest radial spacing proportional to the axial position. wherein the screw has a screw thread and a screw head which rests against a plane bearing surface of the clamping ring, which screw head has a largest diameter which is larger than the largest diameter of the screw thread, wherein the hollow shaft portion has a flattened portion, therefore a region with reduced radial wall thickness compared with the radial wall thickness outside of the region and/or with reduced outer radius compared with the wall thickness outside of the region, wherein the screw, in particular with its screw thread, at least partially rests against the flattened portion, wherein the screw is spaced apart from the shaft, in particular from the outer surface of the shaft, characterized in that the hollow shaft portion has an axial slot, in particular an axial slot passing radially through the hollow shaft portion, and the axial course of the greatest radial spacing of the clamping ring has a constant region adjoined at both sides by a respective rounded region, in particular a circular portion, at whose side remote from the constant region there adjoins a respective linear region in which there runs the greatest radial spacing proportional to the axial position.