Tungsten Electrode — What It Is and Why It Matters
A tungsten electrode is the non-consumable electrode used in TIG welding (GTAW). Tungsten's extremely high melting point (6,170°F / 3,410°C) allows it to sustain the welding arc without melting into the weld pool. The electrode conducts current and creates the arc, but the filler metal is added separately by hand.
Tungsten electrodes come in several types, identified by color-coded tips. Pure tungsten (green) is used for AC aluminum welding. 2% thoriated (red) has been the traditional choice for DC steel and stainless work, though concerns about low-level radioactivity in thorium dust have pushed the industry toward 2% lanthanated (blue) and 2% ceriated (gray/orange) as safer alternatives with comparable performance.
Electrode diameter is selected based on the amperage range — 1/16" for 10-80 amps, 3/32" for 60-150 amps, 1/8" for 100-250 amps. The electrode tip must be ground to a point for DC welding (the taper angle affects arc width and penetration) and balled for AC aluminum welding.
Frequently Asked Questions
Which tungsten color should I buy?
For general-purpose DC welding on steel and stainless, 2% lanthanated (blue) is the best all-around choice — it performs like thoriated (red) without the radioactivity concern and works on both AC and DC. For dedicated AC aluminum welding, pure tungsten (green) or lanthanated both work well.
How do I sharpen a tungsten electrode?
Use a dedicated tungsten grinder or a bench grinder with a diamond wheel reserved only for tungsten. Grind lengthwise (parallel to the electrode, not across it) to create a consistent point. The grind marks should run parallel to the length of the tungsten for a stable, focused arc.