An apparatus for replenishing electrodes in an arc furnace or the like. The apparatus threadedly attaches a replenishment electrode section to a previously installed, presently working electrode section without interrupting the operation of the furnace. The electrode sections are provided with mating terminal threaded portions which are engaged by simultaneousy lowering and rotating the replenishment electrode section. By lowering the replenishment electrode at a faster rate than the lead of the electrode threads and accommodating relative vertical movement of the electrodes, it is not necessary to precisely match the lowering speed of the replenishment electrode with the threads of the electrode. A novel screw-driven, electrically insulated, telescopic drive train is employed for this purpose. The replenishment electrode is carried by a plurality of peripherally spaced wedges actuated independently of the drive train to retain and release the electrode. The telescopic drive train may incorporate either a universal joint in combination with a telescopic connection or reversely wound helical springs which both rotate the electrode and compress to permit the replenishment electrode section to move relatively upwardly during threading.