Zirconiated tungsten electrodes (AWS classification EWZr-1) contain a minimum of 99.10% tungsten and .15 to .40% zirconium. A Zirconiated tungsten electrode produces an extremely stable arc and resists tungsten spitting. It is ideal for AC welding as it retains a balled tip and has a high resistance to contamination. Its current carrying capability is equal to or greater than thoriated tungsten. Under no circumstances is zirconiated recommended for DC welding.