Fluorine alkali type sintering welding flux. welding flux. Fluorine alkali type sintering flux. Basicity about 1.8, spherical shape particles size, 10-60. Excellent welding performance, stable arc burning, slag, weld moulding beauty to weld high low-temperature impact toughness, ac, dc welding wire and meet the positive. AWS A 5.23/A5.17 Welding Flux