Abstract: A clamping device for clamping a workpiece having a center hole, comprises a base member against which the workpiece can be seated, such that the center hole of the workpiece is aligned with a center aperture in the base member. The base member carries outer clamps for clamping an outer portion of the workpiece against the supporting surface. A push member projects through the hole and aperture and carries inner clamps for clamping an inner portion of the workpiece. An actuator displaces the push member for moving the inner clamps to their clamping position, whereupon the push member pushes the outer clamps to their clamping positions. A spring -biased ejector pushes the inner and outer clamps to their non-clamping positions, and ejects the workpiece when the actuator is moved to a release position.