Choosing the right tungsten for the job is almost as important as your ability to do the job. Tungsten electrodes come in color-coded options with various sizes and types to choose from.
So how do you decipher which one is right? Don’t worry, we’ve got you covered in this comprehensive guide.
What Are The Main Types Of Tungstens Used For Welding?
As we progress through this guide of TIG welding electrodes, it’s important to know that there are several TIG welding tungsten options that have the ability to weld a wide range of amperage with both DC and AC. If you stick to the versatile options, you won’t need as many electrodes in your toolbox.
Thoriated Tungsten Electrodes (Red)
Thoriated tungsten is a red color-coded electrode with a principal oxide of 1.7-2.2% thorium oxide. This has long been one of the universal go-to options for any metal and strength for DC compatibility.
Thoriated tungsten has a stable arc and easy start up. It lasts a long time and provides a steady weld. It can handle medium to high amperage as well as low amperage but it also has a tendency to spit a bit when welding.
Thoriated tungsten can work with a variety of metals, including challenging metals like aluminum, nickel alloys, steels, copper, and more. In some industries, this has been the standard multi-purpose TIG welding tungsten to have on hand at all times.
2% Lanthanated Tungsten Electrodes (Blue)
Next, we have a blue color-coded electrode option. Try and use 2% lanthanated TIG Tungsten on whatever you are working on and honestly, you may never go back. You can compare 2% lanthanated to thoriated tungsten in terms of versatility and strength but lanthanated tungsten is non-radioactive, which sets it apart a bit.
The principal oxide of 2% lanthanated tungsten is 1.8 – 2.2 percent lanthanum oxide. There is also a 1.5% lanthanated option but it is slightly inferior and not as versatile. This TIG welding tungsten is great for all-purpose use as well.
The 2% lanthanated tungsten options can be used with all metals like aluminum, steel, magnesium, titanium, nickel alloys, copper, and more! It is also compatible with both AC and DC power. It can be used for alternating currents as well.
Lanthanated tungsten has a solid arc with less spitting. It is stable and solid. The end doesn’t always break cleanly and you may have to use a grinder to cut or score it. Simple arc starts, a wide range of amp compatibility and low erosion rates also contribute to the usefulness of this electrode type.
Zirconated Tungsten Electrodes (White)
And third on our list of the main types of TIG welding tungsten options is Zirconated tungsten. This is another electrode that has always been used as a multi-purpose choice for AC power. When AC options are limited, zirconated tungsten delivers.
Zirconated tungsten has a principal oxide of 0.7 – 0.9% zirconium oxide. Zirconated tungsten can be slightly more limited but it is a good option. It has a solid, steady arc with very little spitting.
In years past, this was the go-to option for AC/DC transformer machines but technology has adapted and new machines have a different inverter setup. If you’re still on one of the older machines, zirconated or pure (green) tungsten may still be a really great option.
Zirconated tungsten can be used with a variety of metals, particularly aluminum and magnesium alloys. It is a non-radioactive material. You can use zirconated tungstens for high amperage cases.
What Welding Processes Use Tungsten Electrodes?
You will hear three names for tungsten electrodes when it comes to welding processes. TIG, GTAW and argon welding are suitable Tungsten processes. Here’s the thing to remember – they are ultimately the same process.
TIG stands for tungsten inert gas and GTAW stands for gas tungsten arc welding. GTAW was the official name at one time but it is now commonly referred to as TIG. An even less common name for GTAW is argon welding. In this type of process, shielding gas is used for welding.
TIG/GTAW uses tungsten electrodes in the welding process. The tungsten electrodes are used to produce the weld and then a filler metal is contributed to make the seal. The external filler metal is often a filler rod but the materials can vary.
It is the electrode that produces the arc for the weld and really does the work. This is why it is so important to choose an appropriate or versatile TIG welding tungsten electrode for your process.
What Lengths Do Tungstens Come In?
This could easily be a trick question. All tungstens are the same length but they have different diameters to measure up to the job at hand. There are different lengths available but you will normally see a length of about 7 inches or 175 mm. It is the diameter that really makes the difference.
Here are the most common diameters used in TIG welding. These diameters are inch measurements but we will show the metric conversion as well.
- .040 (1/0 mm)
- 1/16 (1.6 mm) Very common
- 3/32 (2.4 mm) Very common
- 1/8 (3.2 mm)
- 5/32 (4.0 mm)
- 3/16 (4.8 mm)
When you choose a diameter, the Tungsten electrodes typically come in a 10-pack. You may find that you need several sizes but keep in mind the length is pretty standard while the diameter can vary.
These are the most common diameters you will find but there are manufacturers out there who distribute some varying sizes that are even slightly smaller than what we shared here.
How Do You Choose Tungstens Size?
Choosing your size will vary depending on what you are working on and the TIG process. If you’re a beginner and still working on getting familiar with the different techniques, we recommend that you start out using 3/32, which is 2.4 mm. This is the best option for beginners.
As you become more practiced and more advanced, you will start to get a feel for the varying diameters and will be able to use different sizes if necessary.
In the early stages of TIG welding, it is very easy to accidentally stick the tungsten to the job.
If you are using 1/16 (1.6mm) when unsticking the tungsten from the wok piece, you can easily bend or break them, causing unnecessary cost.
The 3/32 (2.4mm) is a better choice as it has a thicker diameter and is less likely to bend or break when it sticks and you have to unstick it from the job.
This size (3/32 or 2.4 mm) is not overly large but it has a positive strength point and is compatible with the majority of welding amperage needs and ranges.
One more thing to consider is that you may find yourself doing a lot of grinding of the electrode to sharpen it and prepare it. Smaller tungsten sizes tend to snap more easily. Again, this is something that could be easier to adjust to as you become more skilled or you may decide that you will always prefer the mid-size diameter for strength and versatility both.
Is TIG Welding Straight Or Reverse Polarity
Now the question of should you use TIG Tungsten with AC or DC or some other combination? What is the best polarity?
Ultimately, DC polarity is what is most commonly used. However, some tungsten does use AC so be sure you are familiar with the requirements for what you are doing.
There is a process known as DCEN this is DC electrode negative. This is the typical torch polarity setup and uses a negative torch and positive work. This might also be called straight polarity for welders who have been in the game for a long time.
With this method, approximately 2/3 of the heat is transferred to the positive side of the arc and helps to reduce the likelihood of overheating because you have a negative torch.
There is also a DCEP process but it is less common and should not be confused with the process we have detailed above.
What Is The Best Tungsten For Beginner Welders?
We recommend that beginners work with 3/32 TIG Tungsten. We also recommend sticking to 2% Lanthanated tungsten. This type of electrode has a stable and easy arc and is one of the best options available.
In conclusion, let’s review our recommendations, particularly if you are a beginner welder. Don’t let yourself get overwhelmed with the myriad of options thrown at you. Don’t feel like you have to go buy some of every size or type of electrode for your toolbox.
Choose something that is versatile for metals, sizes, strength, and stability and you will be good to go for nearly any project.