Pipe Nipple is used to connect two pieces of pipeline. There are reducing nipple and threaded short nipple. Some people call reducing nipple as Swage Nipple. Similar to pipe reducer, the type of swage nipple is concentric swage nipple and eccentric swage nipple. Manufacture of reducing nipple is MSS SP-95.
Threaded nipple is one kind of forged NPT fittings, if only one end is threaded, it is single end threaded nipple. Both ends are threaded, it is double end threaded nipple.
Threaded nipple. One end is threaded, the other end is plain.