National Pipe Thread (N.P.T) is primarily used for what?

• A. An American standard thread used on threaded pipes.
• B. A metric thread standard used for fasteners.
• C. A thread standard for wood screws.
• D. A standard for external pipe fittings only.

Answer: (A)

National Pipe Thread defines the American standard for threaded pipe connections used in piping systems. The threads are tapered, so when a male NPT fits into a female NPT and a sealant is applied, the joint seals effectively to prevent leaks. This standard is specific to pipes and pipe fittings, not to general fasteners or wood screws, and it covers both male and female threads, not just external fittings.