Abstract: In a fluid-cooled clamp member (1) of a composite electrode (2) of an electric arc furnace, disposed in the flow path (13) for the coolant is a shut-off device (14) which is biassed in the closure direction, having an actuating member (15) by means of which the shut-off device (14) is put into the open condition in opposition to the biassing force, when a replaceable lower portion (2) of the composite electrode, which is subject to burning away, is screwed on. In the event of fracture of the lower portion in the region of the nipple (5), the flow path (13) is closed off by the actuating member (15) being released. The screwthreaded nipple is additionally protected by means of a protective cap which is screwed on to the screwthreaded nipple, the cap having an external screwthread corresponding to the internal screwthread of the lower portion (2).