Rare Earth Tungsten Electrodes (AWS classification EWG) contain a minimum of 98% per cent tungsten and up to 1.5 per cent Lanthanum and small percentages of Zirconium and Yttrium they are called T3 Tungsten. Rare Earth Tungsten Electrodes provide conductivity similar to that of thoriated electrodes. Typically, this means that Rare Earth Tungsten Electrodes are exchangeable with thoriated electrodes without requiring significant welding process changes. E3 delivers superior arc starting, electrode lifetime, and overall cost-effectiveness. When Rare Earth Tungsten Electrodes are compared with 2% thoriated tungsten, Rare Earth Tungsten Electrodes requires fewer re-grinds and provides a longer overall lifetime. Tests have shown that ignition delay with Rare Earth Tungsten Electrodes actually improves over time, while 2% thoriated tungsten starts to deteriorate after only 25 starts. At equivalent energy output, Rare Earth Tungsten Electrodes run cooler than 2% thoriated tungsten, thereby extending overall tip lifetime. Rare Earth 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.