Merit Brass Aluminum Pipe Fitting, Nipple, Schedule 40, 1/2" National Pipe Taper Thread Male x 3" Length (Pack of 25) Nipple for connecting and extending pipes Male National Pipe Taper (NPT) threads for connecting to female threaded pipes Lightweight aluminum metal for less mass than other metals Made from Alloy 6061-T6 for greater strength and corrosion resistance Manufactured from pipes that meet specification ASTM B-241 for quality assurance