Pure tungsten electrodes.
September 16, 2025
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How to Select a Tungsten Electrode Size

Tungsten is a robust metal with unique properties commonly used for the manufacturing of welding electrodes. It has the highest tensile strength of any metal and can retain it even at a high melting point of all at 3422° C (6192° F). This makes it an excellent choice for Gas Tungsten Arc Welding (GTAW), also known as Tungsten Inert Gas (TIG) welding. For TIG welding applications, non-consumable tungsten electrodes assist in forming clean, precise, and high-quality welds.

However, when selecting tungsten electrodes for the welding process, welders must consider many different variables. For example, the type of tungsten electrode, workpiece material, and electrical current play important roles in the final selection. Let’s examine how these considerations inform welders on how to select a tungsten electrode size that will ensure the highest quality performance and weld.

Types of Tungsten Electrodes used in TIG Welding

GTAW, or TIG, welding uses a tungsten electrode to form an arc with the workpiece using an inert gas, generally argon or helium. A perfectly sized electrode is essential in creating a consistent and precise arc. For this reason, electrode selection should be an important part of the welding equipment setup process. The type of tungsten used and the electrical current, discussed below, are major factors that can influence how to select a tungsten electrode size for any welding application.

Selecting the Tungsten Type for TIG Welding Applications

GTAW or TIG welding uses different types of tungsten electrodes for different applications. These electrodes differ in their chemical composition and are color-coded for easy identification, as listed in the table below.

TUNGSTEN ELECTRODE TYPES AND CURRENT OPTIONS

Type of Tungsten Color Code Current Type
Pure Green AC
1% Thoriated Yellow DC
2% Thoriated Red DC
Ceriated Grey AC / DC
1.5% Lanthanated Gold AC / DC
Zirconiated White AC

TIG welding is widely used in industries like aerospace, pharmaceutical, automotive, nuclear, and manufacturing. High-quality and consistent welding results for applications in these industries require the most appropriate tungsten electrode from the list above. Electric current, which is discussed in the following section, must also be considered.

Role of Electric Current in Choosing Tungsten Electrodes 

Some welding processes can use DC as well as AC. The electrical current is responsible for the amount of heat generated on the electrode. To keep balanced heat on the electrode, the tungsten electrode should not be operated at more than the specified current level. Although the tungsten electrode has a high melting point, using a higher than recommended current can cause the tungsten particles to transfer to the weld pool. This can result in a weak or defective weld joint. A lower-than-recommended current, on the other hand, can create an unstable arc. 

Current Level Can Guide How to Select a Tungsten Electrode Size

Different sizes of tungsten electrodes are required for different applications depending upon the material thickness, composition, and power source. It is also always beneficial to follow the manufacturer's recommendation and Welding Procedure Specification (WPS) sheet when setting up welding equipment and selecting the electrode size. Thinner tungsten electrodes can provide a great arc start but have temperature limitations. Thicker electrodes generally withstand more heat and have a longer service life. The diameter of the tungsten and amperage required is also dependent on the base metal being welded. As an example, the following table lists the electrical current range for stainless steel fusion welding applications.

TUNGSTEN ELECTRODE SIZE AND CURRENT FOR STAINLESS STEEL WELDING

Tungsten electrode diameter Amperage
1 mm 10 - 30 amps
1.6 mm 30 – 80 amps
2.4 mm 80 – 150 amps
3.2 mm > 150 amps

For other materials like Inconel®, titanium, or copper, the diameter and amperage range can be slightly higher.

Tungsten is a robust metal with unique properties commonly used for the manufacturing of welding electrodes. It has the highest tensile strength of any metal and can retain it even at a high melting point of all at 3 422° C (6 192° F). This makes it an excellent choice for Gas Tungsten Arc Welding (GTAW), also known as Tungsten Inert Gas (TIG) welding. For TIG welding applications, non-consumable tungsten electrodes assist in forming clean, precise, and high-quality welds.

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