An improved rod for a thermal cutting or burning torch, especially suited for underwater use, is shown to have a metallic outer tube sheath containing exothermic fuel elements within the interior of the tube, providing an open region for the passage of gas to the tip of the tube. The tube is electrically insulated along its outer length, save for an exposed open end adapted to be clamped in an electrically conductive gas-providing cutting torch handle. Within the improved rod, each of the fuel elements consists of a generally ferrous composition having one of two types of coatings. In a first embodiment, an element will be coated with a copper cladding to approximately two percent of the overall weight of the element. In the second embodiment, an element will be clad with either aluminum, or one of the aluminum class of metals, to approximately 4.6 percent by weight, the exact percentage being that percentage required for perfect thermite combustion. In use, the rod containing at least one such element is inserted within an electrically-conducting, gas-providing handle. Pure oxygen is provided, pressurized through the length of the rod, driving water out from the rod and providing a positive oxygen flow. A source of electricity is then provided to the rod and is conducted to the open tip of the rod. A closed electrical circuit is provided between the rod and the object to be cut. Upon striking an arc with the rod, a thermite burning reaction is initiated, which continues even when the supply of electricity is terminated. The rod will burn so long as oxygen is provided, providing a particularly hot cutting flame. With fuel elements of the first embodiment, the flame is found to be as effective or more effective than a thermite cutting rod. With fuel element of the second embodiment, the ability to exactly match the proper portions of aluminum or the aluminum class of metals and iron for a thermite reaction is found to produce a more effective and efficient uniform burning rod. In both embodiments, spurious internal burning, resulting from internal electrical ignition effects, is largely eliminated.