Material: Steel C45, black oxide finish. These couplings do not allow any shaft displacement in axial or radial direction. They should therefore only be used with perfectly alligned shafts. Bore tolerance: +0,05 mm. The torques in the table are maximum values for couplings with keyway. The calculations based on feather-key connection. For couplings without keyway: The transmittable torque is lower and depends on how far the set screws penetrate the shaft.