Abstract: A wedge and clamp device for retaining a wedge in a slot of a disc and against a breaker bar of a rotor assembly in an impact crusher. The clamping arrangement comprises a sleeve which is placed inwardly in the slot, two plates each mounted along the opposed outer faces of the disc in alignment with the sleeve and a bolt extending through the sleeve and two plates. The wedge has a U-groove along its top surface to receive the opposite edges of the disc, and the two plates overlap the wedge so that the wedge can move in a direction out of the slot to increase the holding force against the breaker bar during operation of the crusher.