2% Thoriated (Red) Ewth-2 (Principal Oxide: 1.7-2.2% Thorium Oxide). Overall, Best All Purpose Tungsten Electrode. Best For Use In Direct Current (D/C) Applications Using Transformer Based Constant Current Power Sources. Good D/C Arc Starts And Stability, Medium Erosion Rate, Medium Amperage Range, Medium Tendency To Spit. Best For Use On Non Corroding Steels, Titanium Alloys, Nickel Alloys, Copper Alloys. For Aluminum, Electrically Point Tungsten By D/C Reverse Polarity.