This Anvil plug is a class 150 malleable iron pipe fitting with male National Pipe Taper (NPT) threads for closing and terminating the end of a pipe or fitting. It has NPT threads for creating a tighter seal than straight threads. The plug has a square head for increased leverage and use with a wrench during installation and disassembly. It is made of malleable iron, which has high tensile strength and has a galvanized finish that resists corrosion in water, air and steam applications. This class 150 fitting meets standards ASTM A-197 and ASME B 16.3 for quality assurance. Class is a standard relating to tolerance, construction, dimension and wall thickness, but it is not a direct measurement of maximum working pressure.