Tungsten is an important material used when TIG welding. It is the part of the welding torch that provides the heat to melt the metals being welded together. There are several sizes and styles of tungsten available. The question is what size of tungsten is ideal for TIG welding?
A primarily used material for TIG welding is tungsten. Each of the tungsten rods is suited for a different purpose. The size of tungsten for TIG welding used will depend on many factors. This includes the type of weld, thickness of the material, and the desired output of the welding torch.
In this article, I will explain the most appropriate tungsten rods you need to use for TIG welding. If you are new to TIG welding, this article will help you a lot.
Ideal Size Tungsten For TIG Welding: Complete Guide
Tungsten is used in the TIG welding process to create heat and provide energy. You need to consider several factors including size, shape, and material to choose tungsten. The smaller the tungsten, the hotter it will run, allowing for better arc characteristics. Larger tungsten will run at lower temperatures and are better suited for thicker metals.
Below I describe in detail the size of tungsten you need to use in different types of metal-based on thickness.
- To Weld Aluminum
Tungsten is an exceptional material for TIG welding aluminum. Tungsten electrodes are one of the best methods for welding thin sections of aluminum. Because of the high melting point, tungsten electrodes provide much higher levels of fusion than other welding processes.
This results in reduced levels of internal stress, which can lead to significantly improved strength and durability. While tungsten electrodes are more expensive than other welding processes, the investment is worth it in the long run.
According to the thickness of the aluminum, you need to use the following sizes of tungsten.
| Aluminum Gauge | Joint Type | Tungsten Size | Filler Rod Size |
| 1.6mm | BUTT | 1.6mm | 1.6mm |
| 1.6mm | FILLET | 1.6mm | 1.6mm |
| 3.2mm | BUTT | 2.4mm | 2.4mm/3.2mm |
| 3.2mm | FILLET | 2.4mm | 2.4mm/1.6mm |
| 4.8mm | BUTT | 3.2mm | 3.2mm |
| 4.8mm | FILLET | 3.2mm | 3.2mm |
| 6.4mm | BUTT | 4.8mm | 3.2mm |
| 6.4mm | FILLET | 4.8mm | 3.2mm |
- To Weld Stainless Steel
Tungsten TIG welding is one of the most popular methods for joining stainless steel. One reason for this is the ability to use tungsten sizes that range from small sizes to large sizes. The most commonly used material is a small diameter tungsten rod, but there are also large diameter tungsten electrodes used for welding stainless steel.
This makes it possible to use a single welding machine for a wide variety of applications. However, you need to take the usual precautions when welding stainless steel.
Here is the chart of the different tungsten sizes that are used for TIG welding stainless steel.
| Stainless Steel Gauge | Joint Type | Tungsten Size | Filler Rod Size |
| 1.6mm | BUTT | 1.6mm | 1.6mm |
| 1.6mm | FILLET | 1.6mm | 1.6mm |
| 3.2mm | BUTT | 1.6mm | 2.4mm |
| 3.2mm | FILLET | 1.6mm | 2.4mm |
| 4.8mm | BUTT | 2.4mm | 3.2mm |
| 4.8mm | FILLET | 2.4mm/3.2mm | 2.4mm/3.2mm |
| 6.4mm | BUTT | 3.2mm | 4.8mm |
| 6.4mm | FILLET | 3.2mm | 4.8mm |
- To Weld Low Alloy Steel
TIG welding is a fast welding method that produces a smooth weld with good penetration for welding many types of low alloy steels. The method uses a pulsed gas supply to generate a solid wire electrode, which is moved across the workpiece at high speed. The heat created by the movement of the electrode melts the metal in the weld.
These welding processes have several advantages, such as the ability to produce a much deeper and cleaner weld. This is important for welding low alloy steel. Keep in mind, that mild steel with less than 0.30% carbon and less than 2.5 cm thick rarely requires preheating.
Below is a list of tungsten sizes for low alloy steel based on thickness.
| Alloy Steel Gauge | Joint Type | Tungsten Size | Filler Rod Size |
| 1.6mm | BUTT | 1.6mm | 1.6mm |
| 1.6mm | FILLET | 1.6mm | 1.6mm |
| 3.2mm | BUTT | 1.6mm/2.4mm | 2.4mm |
| 3.2mm | FILLET | 1.6mm/2.4mm | 2.4mm |
| 4.8mm | BUTT | 2.4mm | 3.2mm |
| 4.8mm | FILLET | 2.4mm | 3.2mm |
| 6.4mm | BUTT | 3.2mm | 4.0mm |
| 6.4mm | FILLET | 3.2mm | 4.0mm |
- To Weld Titanium
For welding titanium, the consummate weld quality is determined by the size of the Tungsten Inert Gas (TIG) electrode. The electrode itself cannot make a weld, but the heat produced by the welding arc melts the joint. The heat melts the metal together, and the molten metal creates the weld. If the welding electrode is larger, it can generate more heat and the welding will be better.
Titanium is one of the most common materials used in automotive manufacturing today. It is strong, lightweight, and corrosion-resistant. TIG welding titanium also has several interesting and unique properties. That’s why it is a brilliant choice for several applications.
Below is a tungsten size chart for properly welding titanium TIG.
| Titanium Gauge | Joint Type | Tungsten Size | Filler Rod Size |
| 1.6mm | BUTT | 1.6mm | None |
| 1.6mm | FILLET | 1.6mm | None |
| 3.2mm | BUTT | 2.4mm | 1.6mm |
| 3.2mm | FILLET | 2.4mm | 1.6mm |
| 4.8mm | BUTT | 2.4mm | 3.2mm |
| 4.8mm | FILLET | 2.4mm | 3.2mm |
| 6.4mm | BUTT | 3.2mm | 3.2mm |
| 6.4mm | FILLET | 3.2mm | 3.2mm |
3 Major Types Of Tungsten For TIG Welding
Tungsten is the most common welding rod for Tig welding. This tungsten is highly effective due to producing good welds at both low and high temperatures. Easy to use and handle feature makes it an ideal welding rod for Tig welding. Most Tig welding machines come pre-calibrated for Tungsten welding wire.
Below, I will discuss the main three types of tungsten rods.
- Thoriated Tungsten Electrodes:
These are red coded electrodes and the main oxide is 1.7-2.2% thorium oxide. This is one of the universal options for any metal and energy when considered for DC compatibility.
Prominent features of easy start-up and stable pressure theorized tungsten. Therefore, it provides better joints by lasting longer. You can manage this type of tungsten from medium to high amperage.
You can also weld a variety of challenging metals using thoriated tungsten. Among which are copper, steel, aluminum, etc. Some industries consider it as standard tungsten.
- 2% Lanthanated Tungsten Electrodes:
These are blue color-coded electrodes and the main oxide is 1.8 – 2.2 percent lanthanum oxide. 2% lanthanated TIG tungsten is equivalent to somewhat thoriated tungsten in terms of versatility and strength. The non-radioactive property, however, distinguishes it from thoriated tungsten.
There is a 1.5% lanthanated option on the market. However, these are not as versatile and effective as 2% lanthanated tungsten. These tungsten electrodes may be your best choice for casting many more metals, including titanium, nickel alloys, copper, aluminum, steel.
Lanthanated tungsten is relatively stable and solid, with powerful pressure. You can adjust it with both AC and DC power. You may have to use a grinder to cut it, as these do not always break down cleanly. Low erosion rate and wide amp compatibility help this tungsten to be more useful.
- Zirconiated Tungsten Electrodes:
Zirconiated tungsten electrodes are white-coated and the main oxide is 0.7 – 0.9% zirconium oxide. These are versatile choices for AC power.
These are not radioactive and you can use them for welding various types of metals, especially aluminum and magnesium alloys. Zirconiated tungsten has strong and steady pressure that helps it work seamlessly. Although these are available in limited quantities, they may be a good option.
Length Of Tungsten For TIG Welding:
The length of tungsten remains the same, which is usually 175 mm (about 7 inches). The fundamental difference is in the diameter measurement. Tungsten of different lengths used in TIG welding refers to tungsten of different diameters.
The most frequently used tungsten is 1.6 mm and 2.4 mm in diameter. Other diameters of tungsten used besides these are:
- 1.0 mm
- 1.6 mm
- 2.4 mm
- 3.2 mm
- 4.0 mm
- 4.8 mm
In addition, some manufacturers make tungsten of different diameters, which are smaller in diameter. However, their use is very limited.
Frequently Asked Question
Which Is The Best Tungsten For TIG Welding Stainless Steel?
Thoriated red electrodes are most effective for stainless steel welding. You will need more heat to cast stainless steel properly. These red electrodes provide optimal heat production, bead formation, and joint penetration. That is why better casting is possible.
However, lanthanated tungsten is better than 2% thoriated tungsten for TIG applications. Although thoriated tungsten is ideal in DC TIG, the key problem is radiation. That is why experts recommend lanthanated electrodes for AC and DC TIG.
What Are Differences Between Red and Blues Tungsten?
Thoriated Tungsten Electrode is usually coded in red color and the main oxide is 1.7-2.2% thorium oxide. Blue color-coded electrodes are 2% Lanthanated Tungsten Electrodes and the main oxide is 1.8 – 2.2 percent lanthanum oxide. Although both are equal in terms of strength and versatility, there are some differences between them.
The difference between the two is that blue-coded tungsten is non-radioactive, whereas different studies observed some radioactivity in red-coded tungsten. Red tungsten works well in DC power sources. But blue tungsten is equally suitable for both AC and DC power sources.
Which Colored Tungsten Is Best For Welding Mild Steel?
You need some precautions to weld mild steel. Notable, among which is temperature. This is because welding at high temperatures can damage or deform mild steel. So you have to choose tungsten, which is suitable for casting at low temperatures.
Red tungsten, which contains 2% thorium oxide, is considered the best for mild steel welding. Because this tungsten works well at low temperatures. Besides various challenging metals, it works well in mild steel welding. These are the electrodes that you can use for all purposes.
Final Verdict
Tungsten is a welding alloy that is becoming increasingly popular in the TIG welding industry. It is a much better heat transfer metal than most other welding metals. This makes it the ideal material to use when welding with a TIG welding machine.
But, to weld perfectly, you have to know what size tungsten is ideal for TIG welding. I have explained this in this writing. Hope this article helps you.
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