One of the defining elements of TIG welding is the Tungsten. In fact that is what the first letter in TIG stands for: Tungsten Inert Gas. TIG uses an inert gas to shield the weld (typically Argon), a filler rod of a metal that matches what you are welding, and an electrode made of Tungsten that focuses and directs the arc. All TIG electrodes are more than 95% Tungsten, which is a rare metal used because it is hard and has one of the highest melting points of any metal. There are at least 5 distinct types of “Tungstens”, as most people call them, typically color coated based on how much of what other elements have been added.
Welding certain types of metals require different formulations of Tungsten, and the varieties are color coded. The main colors/varieties of TIG electrodes and their American Welding Society abbreviation are as follows: Green (EWP) = Pure Tungsten, Orange (EWCe-2) = 2% Ceriated, Red (EWTh-2) = 2% Thoriated, Gold (EWLa-1.5) = 1.5% Lanthanated, Brown (EWZr-1) = 1% Zirconiated. There are other colors as well, such as “Grey” Rare Earth, “Purple” Rare Earth and “Yellow” 1% Thoriated, but those 5 are the most commonly used. They all have their drawbacks and benefits, and they all are better at some things then at others, so it is useful to have a variety on hand just in case.
Green – Green electrodes are the least expensive and most common, but they are also the fastest consumed and need to be sharpened frequently. This type of electrode provides a good consistent arc when uses with AC welding of various types, but in DC applications the arc start is poor and it has the lowest current capacity. When heated it easily becomes a perfectly balled tip that is reasonably resistant to contamination.
Orange – Orange electrodes have similar properties to Red, but one additional benefit: no radioactivity. They are great at starting arcs, and welding at lower amperages, with DC or AC, but at higher amperage settings they begin to break down. Ceriated electrodes have a much longer life than Green electrodes in the same usage.
Red – Red electrodes have lots going for them, but the Thorium used in them is slightly radioactive, so be sure you know what procedure should be followed before sharpening them. They feature easy arc starts, great durability, good balling for arc stability, low risk of weld contamination and high current carrying ability at lower amperage settings. They can also be used for both DC and some AC welding, depending on materials.
Gold – Gold electrodes share many of the characteristics of Orange and Red types. They are durable and stable, with good arc starting properties and are suitable for AC and DC welding. The added advantage of these Lanthanated electrodes is their higher current carrying abilities for a given diameter, compared to Green, Red or Orange. They can be used with a balled or pointed end, depending on what you are welding.
Brown – Brown electrodes provide an arc that is extremely stable, because of this they are great for welding with almost no contamination. This type has similar or better current carrying abilities to Red or Orange electrodes in AC applications with a balled end. Brown is never recommended for DC welding.
Purple – Purple is a rare earth alloyed electrode specially formulated to be multi-purpose, and nearly one size fits all. It is much more durable than Green, while not having the radioactive issue of Red. It has excellent arc starting, and arc stability properties. They can be used with nearly any metal, in both AC and DC processes.
Gray – Gray electrodes contain various rare earth elements. Their makeup and characteristics can vary from brand to brand. Each one will list what it is made of and what its intended application is on the package, or catalog description.
Which Tungsten to use is going to be determined by three things, mostly: 1) What metal are you welding? 2) How thick is the metal? 3) Are you using DC, AC sine wave or AC square wave current, and how much? Of course these three things are interdependent. Eastwood carries the Purple E3 Tungsten Electrodes specifically for its wide variety of applications and uses, but here are how the others break down.
Green electrodes are best for AC sine wave welding with a balled tip. They are perfect for aluminum and magnesium applications. It is not a very good choice for ferrous metals, and should not be used for DC welding.
Orange electrodes work great with thin steel, stainless, and nickel because of its ease of starting an arc with lower amperage. This makes it great for sheet metal and very delicate work without risk of burn through. They work best in DC welding with low currents, but can be used for AC welding as well. Using them for higher amperage settings will quickly burn off its oxides making it much less effective.
Red electrodes have similar applications to Orange. They can also be used for AC welding thin aluminum and other materials, and DC welding with straight or reversed polarity on steel, nickel and titanium alloys. Both Orange and Red work best with pointed tips.
Gold electrodes can carry more current for a given diameter electrode without deteriorating. This makes them more suitable for thicker materials. The tip can be pointed, or balled, depending on what and how you are welding. They can be used for AC or DC welding of most metals.
Brown electrodes are perfect for AC welding when you need a balled tip, and you are looking for the lowest contamination possible. These electrodes are never to be used for DC welding processes, however, so it is mostly used for welding aluminum or magnesium.
Eastwood’s Purple E3 electrode was specially alloyed to be useable in just about any application. It burns cooler and is more durable than the Red electrodes, without the radioactivity. It features better arc starts at lower power setting than most other electrodes, and a stable arc for more accurate welds. It can handle higher currents than Red or Orange electrodes without deterioration of the tip, or contamination of the weld. Purple electrodes can be used to weld all steels, titanium, nickel, magnesium and aluminum in all DC and AC processes.
Check out the Eastwood Blog and How-To Center for more Tips and Tricks to help you with all your automotive projects. If you have a recommendation for future articles or have a project you want explained don’t hesitate to leave a comment.