Threaded One End (TOE) Pipe Nipples have threading on one end and is used to make mechanical joints and the other end is often connected by weld.
Pipe Adapters
Pipe Adapters
Pipe adapters are very similar to Hex Bushings in that they feature both a female thread and a male thread. The difference is Hex Bushings are used to reduce the size of the pipe line and and Pipe Adapters are used when connecting two pipes of different types.