Sometimes non-consumable electrodes are included as well, but since these metals are not consumed by the welding process, they are normally excluded.

They can use either direct (DC) or alternating (AC) current, and consumable or non-consumable electrodes.

Non-consumable electrode processes, such as gas tungsten arc welding, can use either type of direct current (DC), as well as alternating current (AC).

Non-Consumable Electrode Processes - e.g. gas-tungsten arc welding (GTAW), plasma arc welding (PAW), and fusion welding.

Orbital welding has almost always exclusively been carried out by the Tungsten Inert Gas (TIG / GTAW) technique using non-consumable electrodes, with additional cold-wire feed where necessary.

Gas tungsten arc welding (GTAW), or tungsten/inert-gas (TIG) welding, is a manual welding process that uses a non-consumable electrode made of tungsten, an inert or semi-inert gas mixture, and a separate filler material.