Miller Weldcraft WL2040X7 2% Lanthanated Tungsten Electrode .040 X 7", 2% Lanthanated (Blue) EWLa-2/WL20 Principal Oxide: 1.8  2.2% Lanthanum Oxide Non-Radioactive. Best general purpose electrode for both Alternating Current (A/C) or Direct Current (D/C) using inverter or transformer based constant current power sources. Good for low-alloyed steels, non corroding steels, aluminum alloys, magnesium alloys, titanium alloys, nickel alloys, copper alloys. Good arc starts and stability, medium to high amperage range, low errosion rate.