What Is an NPT Pipe Tap?

An NPT pipe tap is a threading tool used to create or restore the internal tapered threads found in NPT pipe connections. NPT stands for National Pipe Thread, a widely used pipe-thread standard for connecting pipe, fittings, valves, and other threaded components. Unlike straight machine threads, NPT threads are tapered. The thread diameter gradually increases along the threaded length, allowing male and female NPT threads to tighten progressively as they are assembled.

What Are Carbon Steel NPT Pipe Taps Used For?

Carbon steel NPT pipe taps are particularly useful for cleaning, chasing, repairing, and restoring existing internal pipe threads. Threads can become difficult to use because of corrosion, dirt, debris, cross-threading, or other damage. Running the correct size NPT pipe tap through an existing threaded hole can help clean the threads and restore their shape so a matching male NPT fitting can properly engage.

These taps are useful for maintenance, repair, plumbing, automotive, fabrication, industrial, and general shop applications.

Carbon Steel Construction

These NPT pipe taps are manufactured from carbon steel with a bright, uncoated finish. Carbon steel taps provide a practical solution for general-purpose pipe thread maintenance, cleaning, and repair. They can be used with a variety of ferrous and non-ferrous materials when appropriate tapping practices and cutting fluids are used.

Applications

Carbon Steel NPT Pipe Taps are well suited for:

• Pipe fittings
• Valves
• Plumbing components
• Threaded pipe connections
• Manifolds
• Pneumatic components
• Hydraulic components
• Machinery and equipment
• General maintenance and thread repair

Understanding NPT Pipe Tap Sizes

NPT pipe tap sizes are based on nominal pipe size, meaning the size shown on the tap does not represent the actual outside diameter of the tap or the diameter of the required hole. Each NPT size also has a specified number of threads per inch (TPI). Always match the tap to the correct NPT size and thread pitch of the fitting or threaded connection.

Frequently Asked Questions

What is an NPT pipe tap?

An NPT pipe tap is a threading tool used to create or restore internal National Pipe Thread (NPT) threads. NPT threads are tapered and are commonly found in pipe, fittings, valves, and other threaded connections.

Do NPT Threads Require Thread Sealant?

NPT connections normally require a suitable thread sealant to help create a leak-resistant connection. Common options include PTFE thread-seal tape and pipe-thread sealing compounds. Always choose a sealant appropriate for the materials, pressure, temperature, and fluid or gas involved in the application.

What are carbon steel NPT pipe taps used for?

Carbon steel NPT pipe taps are commonly used for cleaning, repairing, and re-threading damaged or jammed internal pipe threads. They can help restore existing NPT threads so a matching male fitting can properly engage.

Can an NPT tap repair damaged pipe threads?

Yes. An NPT pipe tap can be used to clean and restore damaged, dirty, corroded, or jammed internal NPT threads, provided the existing threads are not damaged beyond repair.

What does NPT mean?

NPT stands for National Pipe Thread. It is a tapered pipe-thread standard commonly used for threaded pipe, fittings, valves, and other connections.

Is the listed NPT size the actual diameter of the tap?

No. NPT sizes are nominal pipe sizes. The size designation does not represent the actual outside diameter of the tap or the diameter of the required drilled hole.