Stainless Steel 316 Pipe Fitting, Union, Class 1000, 1-1/2" NPT Female Union for connecting and extending two male pipes Female National Pipe Taper (NPT) threads for connecting two male threaded pipes Made from stainless steel 316 for strength Higher corrosion resistance than stainless steel 304 Meets standards ASTM A182, ASME SA182, and ANSI B16.11 for quality assurance