Where should pipe joint compound be applied?

Pipe joint compound is a sealing agent used to ensure a leak-proof joint in plumbing connections. When considering where to apply it, it's important to understand the threading system of the pipes. The correct practice is to apply pipe joint compound to the male threads only.

Male threads are protruding threads that are designed to fit into the female threads of a fitting or another pipe. By applying the compound to the male threads, it creates a seal when the connection is made with the female threads, filling any small gaps that could lead to leaks. This ensures a tight, secure joint that can withstand the pressures of the fluid being transported.

Applying the compound solely to the male threads also streamlines the process and reduces the potential for excess material, which could otherwise squeeze out during tightening and create complications.

In contrast, applying the compound to the female threads is not recommended as these joints are designed to fit cleanly against the male threads without the need for a compound. Therefore, applying it only to the male threads is the standard practice for ensuring effective sealing in plumbing systems.