Anderson Metals Brass Pipe Fitting, Coupling, 1/2" x 1/2" Female Pipe Coupling for connecting two pipes with the same diameter in a straight run Female National Pipe Taper (NPT) threads for connecting to male threaded pipes. The ID of the  coupling would be close to . Brass for corrosion resistance, ductility at high temperatures, and low magnetic permeability Operating temperatures range from -53 to 121 degrees C (-65 to 250 degrees F) Meets specifications ASTM B584 and ASME/ANSI B16 for quality assurance These fittings contain lead and are not allowed by federal law to be installed for potable water use in the U.S.A. and its territories.