There are many tungsten electrode types, so how to identify select and prepare tungsten electrodes is very important for your application.Tungsten electrode is an important part in TIG (or GTAW) welding. Because tungsten electrode has many good properties such as high hardness and high temperature resistance to carry the welding current to the arc, and it has the highest melting point of any metal so it can be used in high temperature environment and without quickly loss.

These non-consumable tungsten electrodes come in a variety of sizes and lengths and are composed of either pure tungsten or a hybrid of tungsten and other rare earth elements and oxides. According to the raw material it can be divided into these types: pure tungsten electrode, 2%thoriated tungsten electrode, 2% ceriated tungsten electrode, 1.5% lanthanated tungsten electrode, zirconiated electrode and other rare earth tungsten electrode. Choosing an electrode for the TIG process not only depends on the base material type and thickness, but also depends on welding alternating or direct current. There is a selection guide for selecting different type tungsten electrode.

Pure tungsten electrodes during welding can provide great arc stability for AC welding with balanced wave especially on aluminum and magnesium, but is not typically used for DC welding.
2% thoriated tungsten electrodes can increases electrode’s electron emission qualities, having lower consumption and eliminates arc wandering for greater stability. And it can use for welding some small thin steel and parts. But it has radioactivity and are only for specialty type AC welding.

2% ceriated tungsten not only can perform best in DC welding at low current settings but can be used proficiently in AC or DC processes. But using ceriated electrodes at higher amperages is not recommended.

1.5% lanthanated tungsten electrodes have excellent arc starting, low-burn-off rate, good arc stability and excellent re-ignition characteristics. It can work well on AC or DC electrode negative with a pointed end or they can be balled for use with AC sine wave power sources.

Zirconiated tungsten electrodes can produce an extremely stable arc and resists tungsten spitting. It is ideal for AC welding as it retains a balled tip and has a high resistance to contamination.

Rare earth tungsten electrodes has stable arc in both AC and DC processes, greater longevity than thoriated tungsten, the ability to use a smaller size diameter tungsten for the same job, use of a higher current for similar sized tungsten and less tungsten spitting.