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.

Hex bushings are used to reduce the size of female threads from a larger to a smaller diameter. Hex Bushings are threaded fittings that have male threads on the outside and female threads on the inside with a hex head used to tighten the fitting into the threaded opening. Merchant steel fittings are designed with Dryseal Taper Threads (NPTF) for more critical applications. NPTF Dryseal threads produce a mechanical seal by the mating and slight crushing of the threads when a wrench is applied to tighten the fittings.