Pure Tungsten contains a minimum of 99.5wt-% Tungsten with no other alloying elements. This allows the tip to form a clean, balled end which provides good arc stability on AC. Pure can be used with DC but does not compare with Thoriated or Cerated as far as ease of are starting. More susceptible to weld contamination than Thoriated, Cerated or Lanthanated.
Usually the least expensive of all Tungsten. Pure Tungsten is generally used in the welding of aluminium and magnesium alloys (AC).