As a welder, I’m often asked what color tungsten for stainless steel. It’s crucial to choose the right one, as it can significantly impact the repeatable quality of your weld. In this article, I’ll share my insights on the five main types of tungsten electrodes and their suitability for welding stainless steel. Plus where I would use each tungsten for long periods of welding the different types of stainless steel.
The color of a tungsten electrode indicates its chemical composition. I have chosen 5 different color tungstens that will be best suited to specific types of TIG welding stainless steel. My recommendations are Blue, Purple, and Red tungstens.
1. RED Thoriated Tungsten
Thoriated tungsten electrodes, containing 1-2% thorium oxide (ThO2) , are ideal for high-amperage welding of stainless steel. Although they have a slightly lower melting point than pure tungsten (3380°C), they are mildly radioactive. The benefits of using thoriated tungsten electrodes include the following:
- Maintaining a sharp point
- Superior arc stability
- Good current carrying capacity
- Very popular in the welding industry
- Can be snaped to shorten
It’s essential to note that the mild radioactivity of thoriated tungsten electrodes has led some welders to opt for alternative options. I have an article on how to sharpen a tungsten safely, this deals with radioactive dust.
Red Tungsten For Heavy Wall Stainless Steel Pipe Welding
I have been on many petrochemical, LNG, and food or pharmaceutical plants for over the 20-plus years welding stainless steel. For heavy wall stainless steel, RED Thoriated tungstens were supplied. Mainly because the welding procedures were already set.
But the red tungstens can handle continued high amperage welding. Some pipes can be 24″ and 2″ thick. Hours of 180 amps plus welding. They handled the punishment.
2. Blue Lanthanated Tungsten for Stainless Steel
I’ve discovered that a 2% Lanthanated Tungsten electrode can effectively replace a wide range of tungsten types in most welding applications, making it a versatile and cost-effective choice.
Lanthanated electrodes are made with lanthanum oxide (La2O3), providing the electrode with the ideal balance between oxide evaporation, oxide migration, and overall function.
The point stays sharp
More versatile for different material
Easy arc starts
Doesn’t break clean, when shortening
Lanthanated tungsten enables me to start and maintain my arc at lower voltage levels. Simultaneously, I can increase the current by up to 50% for any electrode size I might use.
The inclusion of lanthanum oxide endows Lanthanated Tungsten with exceptional stability, life, arc, and versatility. I’ve experienced far less contamination in my welds from the electrode mixing metals, which is a significant advantage. Moreover, Lanthanated Tungsten has zero radioactive hazard levels, making it a much safer option compared to some alternatives.
Blue Tungstens for A Range Of Stainless Steel Thicknesses
I would use this tungsten in a home shop or for a welding contractor that has a wide variety of stainless steel welding requirements. For a full explanation of 2% lanthanated tungstens read the full article.
3. Gold Lanthanated 1.5% Color Tungsten
Throughout my career, I have found that 1.5% lanthanated tungsten is an effective choice for welding stainless steel, But I wouldn’t be buying a ten-pack for use at home or in a small jobbing shop.
1.5% lanthanated electrodes have a composition of 97.80% tungsten and 1.30% to 1.70% lanthanum oxide (La2O3). They possess outstanding arc starting and stability, low burnoff rate, and exceptional reignition characteristics. These electrodes exhibit the same conductivity properties as 2% thoriated tungstens, making them a viable substitute without requiring significant modifications to a welding program.
In comparison to pure tungsten, the addition of 1.5% lanthanum increases the maximum current-carrying capacity by approximately 50% for a given electrode size. The arc can also be started and maintained at lower voltages, similar to ceriated electrodes.
Gold Lanthanated 1.5% For Tig Welding Stainless Steel
The gold tungstens aren’t as popular as the 2% lanthanated tungsten. They can weld as good as the thoriated but I find the tip looses its fine point quickly if you are using a 15-20 degree angle. This costs time and money. You have to either switch ends or replace or sharpen them
So they aren’t my first choice. Plus they don’t do great on AC. But that’s another article.
4. Grey Ceriated Tungsten For Welding Stainless Steel
Ceriated tungsten electrodes contain 1-2% cerium oxide (CeO2) and are suitable for medium amperage welding of stainless steel. They have a melting point of 3380°C, which is the same as thoriated tungsten, but they are not radioactive. Using ceriated tungsten electrodes offers several benefits.
- Not as good at maintaining a sharp point
- Excellent arc stability
- Good current carrying capacity
- Shorter lifespan compared to thoriated tungsten
Grey Ceriated Tungsten For Welding Thin Stainless Steel
When I was contracting as a stainless steel sheet metal worker a lot of my co-workers used Ceriated tungstens for the low amperage and long life. A lot of the guys were running 1/16th or 1.6mm. These wouldn’t be on my shopping list if I was buying a ten-pack of tungstens. They don’t seem as versatile.
5. Purple Tungsten For Stainless Steel
If you’re looking for an alternative to thoriated tungsten electrodes, look at the Purple Tungsten electrode, also known as the E3 electrode. As thoriated electrodes become less common because of their radioactive content.
Here’s why the E3 electrode, with its non-radioactive properties, is a superior alternative to thoriated tungsten electrodes:
- Cooler electrode tip: The Purple tungsten electrode maintains a cooler tip compared to thoriated tungsten, resulting in improved performance and reduced wear.
- Superior repeatable ignition characteristics: The electrode offers consistent and reliable ignition, ensuring a smooth and efficient welding experience.
- Increased arc stability: The electrode provides enhanced arc stability, allowing for more precise and controlled welds.
- Reduced burn-off: The electrode experiences less burn-off during welding, leading to longer electrode life and reduced maintenance.
- Improved tip degradation: Less tip degradation compared to thoriated tungsten, further extending its lifespan and reducing the need for frequent sharpening or replacements.
For example, when using the same current density, the purple tungstens are approximately 900 degrees C cooler than Red Tip tungstens. This significant temperature difference translates to better overall performance and increased longevity.
As the welding industry shifts towards safer and more efficient options, the Purple Tungsten electrode is quickly gaining popularity. With its numerous advantages over traditional thoriated tungsten electrodes, the E3 electrode is an excellent choice for welders seeking a high-performance, non-radioactive alternative.
Summary Of Which Color Tungsten for Stainless Steel Welding
The selection of tungsten electrodes for gas tungsten arc welding stainless steel relies on the amperage and specific requirements of the welding task. Thoriated tungsten for high amperage welding, and ceriated tungsten for medium amperage welding. Each type of tungsten electrode offers benefits such as superior arc stability, good current carrying capacity, and extended lifespan.