-4ANFemaleAlWeldBung, Universal, AN Fitting, Female -4AN Aluminum Weld Bung (7/16" - 20 Thread, 3/4" Flange OD), Female -4AN Aluminum Weld Bung (7/16" - 20 Thread, 3/4" Flange OD), ALUMINUM WELD BUNGS, Vibrant Performance female AN bungs are available in both aluminum & mild steel and range from -4 to -16 AN thread sizes.