A clamping device for releasably holding a tool holder shank includes a housing, a drawbar axially moveable in a bore in the housing between an advanced releasing position and a retracted locking position, engagement members moveable under the effect of the drawbar into locking engagement with the tool holder shank, and a sleeve arranged around a wall of the housing and axially moveable in relation to it. A first wedge is received in a first aperture in the wall and configured to move the drawbar rearwards in the bore when pressed radially inwards in the aperture by movement of the sleeve in a first axial direction. A second wedge is received in a second aperture in the wall and configured to move the drawbar forwards in the bore when pressed radially inwards in the aperture by movement of said sleeve in an opposite axial direction.