CK T187G Pure Tungsten Electrode 1/8" X 7" Pack of 10 Pure (Green) EWP/WP Principal Oxide: None Non-Radioactive. Good for use in Alternating Current (A/C) for aluminum alloys and magnesium alloys in low to medium amperage applications using transformer based constant current power sources only. Balls easy, tends to spit at higher amperages. Used for non-critical welds only.