Abstract: The invention relates to a multi-disc brake comprising a stationary rotary disc (1) and a movable rotary disc (2) which is mounted on a splined sleeve (5) sliding on a splined part (3a) of a hub (3) which has an axis (4) and with which the disc (1) is solid. An assembly of friction blocks (6 to 9) can interact with the discs (1, 2) under the action of a hydraulic jack (13). These blocks occupy a limited angular sector over the periphery of the discs. The splines (23, 25) of the hub and of the sleeve have shaped flanks. A ring (30) for guiding the sleeve (5) radially relative to the hub (3) is provided at each of its ends, so as to prevent any jamming of the sleeve (5) because of the tendency of the disc (2) to rock under the action of the jack (13).