direction of its eccentricity or unbalanced mass is as precisely as possible situated opposite that of the holding device with respect to the axis of rotation 19 as a result the eccentricities or unbalanced masses 34 a 34 and 34 b 34 compensate one another with the exception of the residual amount 34 c 34 of a resulting eccentricity or unbalanced mass 20 for reasons of clarity fig2 shows profiles 11 12 with only three wedges 13 and 15 in order to permit a more precise compensation of eccentricities or unbalanced masses the profiles 11 12 are advantageously provided with more than three preferably with six wedges fig6 which permit an inserting of the clamping chuck in positions swivelled by 60 u00b0 respectively the clamping chuck 4 is inserted with a 34 lead 34 in the sense that its marking 18 during the counterclockwise rotation can move in the direction of the marking 17 on the receiving device 3 in this case the joining gap is first eliminated and then the frictional engagement is achieved with such a high contact pressure that the machining torque can be absorbed in this frictional engagement the clamping chuck 4 can then be rotated still farther until the markings 17 18 are situated approximately opposite one another as a rule a rotating angle of up to 30 u00b0 is available for this rotation so that the markings 17 18 and therefore the eccentricities.