Chrome-Plated Brass Pipe Fitting, Nipple, Schedule 40, 1/2" NPT X 2-1/2" Length Nipple for connecting and extending pipes Male National Pipe Taper (NPT) threads for connecting female threaded pipes Made from brass for higher corrosion resistance than steel Relative softness of metal enables tighter seals and greater ease in installation.Meets standard NSF/ANSI 61 for use in drinking water supplies of pH 6.5 and higher Note: Please refer the document for How to Measure Threaded Pipe and Pipe Fittings.