Swirl rings direct the plasma stream as it travels around the electrode and into the nozzle on compatible plasma torches. Sometimes called start cartridges, gas distributors, or baffles, they swirl the plasma gas around the electrode, which helps narrow the plasma stream and minimize beveling on the edge of the cut. The swirling action of the gas causes heavier un-ionized gas molecules to move to the edges of the nozzle, which helps cool the nozzle and extend its life. Swirl rings also maintain proper alignment of the nozzle and the electrode, and they electrically insulate the nozzle and the electrode from one another. They are compatible with specific brands and series of plasma torches, and damaged swirl rings must be replaced to maintain the performance of the plasma torch. A complete plasma torch assembly includes a swirl ring, nozzle, retaining cap, shield cap, and electrode.