SFA-5.12/SFA-5.12M: Specification for Bare Tungsten and Tungsten Alloy Electrodes for Arc Welding and Cutting

This specification includes the requirements for bare tungsten and tungsten alloy electrodes used for welding and cutting with GTAW and PAW. Tungsten electrodes are not consumed during welding or cutting; they are instead used to establish the electric arc. The classification starts with the letter “E” for electrode and is followed by the symbol “W” for tungsten. Either the letter “P” for pure or the type of oxide alloyed with the tungsten follows the “W” designator. The remaining number designator indicates the percent of oxide. For example, the classification EWTh-2 is an electrode (E) that is made of tungsten (W) having a thorium oxide or thoria (Th) content of 2% (-2). Tungsten electrodes designated as EWTh-2 are the most prevalent and are commonly referred to as 2% thoriated tungsten electrodes.