What is Green Tungsten Used for?

Selecting the right electrode is essential for a good TIG (tungsten inert gas) weld. Tungsten electrodes are color-coded to indicate their chemical composition, and one of the most common types is the pure tungsten electrode, identified by its green tip.

This guide will explain the properties of pure tungsten electrodes and their primary applications in welding.

What is a Pure (Green) Tungsten Electrode?

A pure tungsten electrode is made of 99.5% pure tungsten. This makes it a very simple, non-alloyed electrode. When heated, its tip forms a clean, balled shape, which provides excellent arc stability for AC (Alternating Current) welding.

Properties of Pure Tungsten (Green) Electrodes

• Composition: 99.5% pure tungsten.
• Arc Stability: Provides a very stable arc, especially for AC welding with a balanced sine wave.
• Tip Formation: Forms a balled tip when heated, which helps maintain a steady arc.
• Durability: Has a lower burn-off rate than other alloyed electrodes.
• Price: Inexpensive than high-alloyed electrodes.

What is a Green Tungsten Electrode Used For?

Pure tungsten (green) electrodes are specifically designed for AC welding. Their unique properties make them the ideal choice for welding certain types of metals.

• Aluminum and Magnesium: The best option for welding magnesium and aluminum alloys is green tungsten. Its ability to form a stable, balled tip is perfect for the fluctuating polarity of AC welding, which is required for these metals.
• Low to Medium Amperage: Pure tungsten electrodes perform best in applications with low to medium amperage requirements. For higher amperage applications, other alloyed electrodes are often a better choice.
• AC Sine Wave Welding: The green electrode is particularly well-suited for use with older-style AC sine wave welding machines.

Limitations

While pure tungsten electrodes are excellent for AC welding, they are generally not used for DC welding. For DC applications, electrodes with rare-earth additives like cerium or thorium provide a much stronger arc and better arc starting capabilities.

Additionally, pure tungsten electrodes tend to have a higher burn-off rate and are not as durable as alloyed options. They also require more effort to achieve arc stability compared to other electrodes.

Conclusion

Every welder should have pure tungsten (green) electrodes, especially when AC welding magnesium and aluminum. Their affordability and ability to form a stable, ball tip make them a reliable choice for these specific applications. For DC welding or applications requiring a stronger arc start, other color-coded electrodes would be a better choice.