Swage Nipples (also referred to as swages) are Reducers for piping systems that are given their name due to the process of their manufacture. Swaging is a metal-forming technique in which the metal is plastically deformed to its final shape using high pressures, either by pressing or hammering, or by forcing the material through a die. Swaging differs from forging in that the swaged metal is cold worked, and the output of the swaging operation is usually the finished shape: they are cold formed from two pieces slamming into each other at high pressures. These pieces are longer than Reducers, and are used more extensively in higher pressure applications.
Swages contain a bore, usually matching that of the pipe onto which they are fitting. Because each end is of a different size, the bore – as well as the wall thickness and schedule – of each side can also be different. The swage ends can be plain (PBE, for plain both ends), threaded (TBE, for threaded both ends), bevelled (for butt-welding; BBE, for bevelled both ends), or a combination thereof, depending on the ends of the piping system into which the swage will be fitted.