Lead Free Brass Pipe Fitting, Threaded Companion Flange, Class 150, 3" NPT Female Specification Met: ASME B16.24, NFS-61, ASTM B584 Female National Pipe Taper (NPT) threads for connecting to male threaded pipes Bolt holes to connect to other bolted flanges or flat surfaces Made from lead-free brass for higher corrosion resistance than steel Manufactured to standard ASTM B-584-06 for lead-free quality assurance