Which end of a threaded hose coupling is cut on the interior surface of a swivel?

The correct choice is the female end because this component is where the threads are designed to allow for a secure fit when connecting two sections of hose. In a threaded coupling, the female end has internal threads that provide a connection point for attaching the male end, which has external threads.

The design of the female coupling's interior surface is important for maintaining the integrity of the coupling. A cut or tapered edge is often present on the interior surface of the female coupling to facilitate easier assembly and ensure a snug fit when the male end is inserted. This design not only helps in connecting the hoses more efficiently but also prevents leaks and maintains pressure during use.

Understanding this design aspect is crucial for firefighters when they are preparing hoses for use, as it impacts how quickly and effectively they can establish water supply lines during operations.