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VIPER MIG 165
OPERATING MANUAL
TIG: Welding Guide
Tungsten Electrodes
• Tungsten is a rare metallic element used for manufacturing TIG welding electrodes. The TIG process relies on
tungsten’s hardness and high-temperature resistance to carry the welding current to the arc. Tungsten has the
highest melting point of any metal, 3,410 degrees Celsius.
• Tungsten electrodes are non-consumable and come in a variety of sizes; they are made from pure tungsten or an
alloy of tungsten and other rare earth elements. Choosing the correct tungsten depends on the material being
welded, the number of amps required and whether you are using AC or DC welding current.
• Tungsten electrodes are colour-coded at the end for easy identification.
• Below are the most commonly used tungsten electrodes found in the New Zealand and Australian market.
Thoriated
Thoriated tungsten electrodes (AWS classification EWTh-2) contain a minimum of 97.30 per cent tungsten and 1.70 to
2.20 per cent thorium and are called 2 per cent thoriated. They are the most commonly used electrodes today and
are preferred for their longevity and ease of use. Thorium, however, is a low-level radioactive hazard and many users
have switched to other alternatives. Regarding the radioactivity, thorium is an alpha emitter, but when it is enclosed
in a tungsten matrix, the risks are negligible. Thoriated tungsten should not get in contact with open cuts or wounds.
The more significant danger to welders can occur when thorium oxide gets into the lungs. This can happen from
the exposure to vapours during welding or ingestion of material/dust in the grinding of the tungsten. Follow the
manufacturer’s warnings, instructions, and the Material Safety Data Sheet (MSDS) for its use.
E3 (Colour Code: Turquoise)
E3 tungsten electrodes (AWS classification EWG) contain a minimum of 98% percent tungsten and up to 1.5 percent
Lanthanum and small percentages of Zirconium and Yttrium they are called E3 Tungsten. E3 Tungsten Electrodes
provide conductivity similar to that of thoriated electrodes. Typically, this means that E3 Tungsten Electrodes are
exchangeable with thoriated electrodes without requiring significant welding process changes. E3 deliver superior
arc starting, electrode lifetime, and overall cost-effectivenes. When E3 Tungsten Electrodes are compared with 2%
thoriated tungsten, E3 requires fewer re-grinds and provides a longer overall lifetime. Tests have shown that ignition
delay with E3 Tungsten Electrodes actually improves over time, while 2% thoriated tungsten starts to deteriorate after
only 25 starts. At equivalent energy output, E3 Tungsten Electrodes run cooler than 2% thoriated tungsten, thereby
extending overall tip lifetime. E3 Tungsten Electrodes work well on AC or DC. They can be used DC electrode positive
or negative with a pointed end, or balled for use with AC power sources.
Ceriated (Colour Code: Grey)
Ceriated tungsten electrodes (AWS classification EWCe-2) contain a minimum of 97.30 per cent tungsten and 1.80 to
2.20 per cent cerium and are referred to as 2 per cent ceriated. Ceriated tungstens perform best in DC welding at
low current settings. They have excellent arc starts at low amperages and become popular in such applications as
orbital tube welding, thin sheet metal work. They are best used to weld carbon steel, stainless steel, nickel alloys, and
titanium, and in some cases, it can replace 2 per cent thoriated electrodes. Ceriated tungsten is best suited for lower
amperages it should last longer than Thoriated tungsten higher amperage applications are best left to Thoriated or
Lanthanated tungsten.
Lanthanated (Colour Code: Gold)
Lanthanated tungsten electrodes (AWS classification EWLa-1.5) contain a minimum of 97.80 per cent tungsten and 1.30
per cent to 1.70 per cent lanthanum and are known as 1.5 per cent lanthanated. These electrodes have excellent arc
starting, a low burn-off rate, good arc stability, and excellent re-ignition characteristics. Lanthanated tungstens also
share the conductivity characteristics of 2 per cent thoriated tungsten. Lanthanated tungsten electrodes are ideal if
you want to optimise your welding capabilities. They work well on AC or DC electrode negative with a pointed end, or
they can be balled for use with AC sine wave power sources. Lanthanated tungsten maintains a sharpened point well,
which is an advantage for welding steel and stainless steel on DC or AC from square wave power sources.
Zirconiated (Colour Code: White)
Zirconiated tungsten electrodes (AWS classification EWZr-1) contain a minimum of 99.10 per cent tungsten and 0.15 to
0.40 per cent zirconium. Most commonly used for AC welding Zirconiated tungsten produces a very stable arc and
is resistant to tungsten spitting. It is ideal for AC welding because it retains a balled tip and has a high resistance to
contamination. Its current-carrying capacity is equal to or greater than that of thoriated tungsten. Zirconiated tungsten
is not recommended for DC welding.