Universal, Multi-Purpose Fitting, Female 1/2" -14NPT Mild Steel Weld Bung (1-1/4" OD), Female 1/2" -14NPT Mild Steel Weld Bung (1-1/4" OD), STEEL WELD BUNGS, Weld Bungs, Vibrant Performance female NPT bungs are available in both aluminum & mild steel and range from 1/8" to 1" thread sizes., 1/2"NPTFemMSWeldBung.