Abstract: Roller clamps provide an economical and effective means to achieve steady and uniform current distribution through the anodes and cathode of an Hall-Heroult electrolytic cell during the pre-heat cycle. The roller clamps, which replace conventional bar clamps that are used in normal operation, have rollers adapted to bias anode support rods against electrical contacts on an anode bus bar with sufficient pressure to maintain desired electrical contact between the anode and contact; and to permit the anode supports to move to accommodate thermal expansion or deflections of cell components as the cell is heated.