An electrode is provided for the resistance welding of bolts, having an upper part and a lower part which are configured to be connectable together and, in the connected state, jointly provide a cavity, the upper part having an opening for introducing a bolt, and the lower part having a gas connection for a pressurized gas. A valve body, by way of which the opening is closable, is arranged in the cavity. As a result, applied compressed air is prevented from flowing out. Compressed air only emerges when the valve body opens up the opening.