TIG welding electrodes usually contain small quantities of metallic oxides which can offer the following benefits: -Facilitate arc starting -Increase arc stability -Improve current carrying capacity of the electrode -Reduce the risk of weld contamination -Increase electrode lifeOxides used are primarily zirconium, thorium, lanthanum or ceriumAdditions are 1% - 4%, improve arc initiation, especially when direct current (DC) welding is employedThorium oxide (thoria), effective in terms of long life and thermal efficiencyZirconium oxide (zirconia) has been commonly used for alternating (AC) TIG welding, welding aluminumElectrode length: 7"Each package contains 10 electrodes; Pure:Lowest current capacity and least expensiveMaintains a clean balled end for welding on ACMore prone to weld contamination than other types of tungsten electrodesTends to spit at higher currentsUsed for non-critical welds only