How to Use Plumber's (Teflon) Tape

The Spruce / Kevin Norris

What Is Plumber's (Teflon) Tape?

Plumber's tape or Teflon tape is a polymer that is made of polytetrafluoroethylene (PTFE). Teflon is the trademark name Chemours (formerly Dupont) has for the polymer. You can't find a product called "Teflon tape" on shelves; instead, it's labeled "thread seal" or "thread-sealing" tape. Confusing matters, "plumber's tape" is a name used for metal or plastic strapping used to support pipe.

Historically, it got the common name "Teflon tape" when manufacturers began using Teflon in their thread-sealing tapes and would list the trademarked ingredient on its packaging.

Before You Begin

Not all plumber's (Teflon) tape is the same. Before grabbing a roll, get the right kind for your needs. These tapes are color-coded according to their use. Here's the difference between them:

• White or pink tape: Commonly used by plumbers and pipe fitters for water lines; white is the more common type; pink is sturdier and often used by pipe fitters
• Yellow tape: Used for gas lines; meets gas company standards for propane, butane, and natural gas
• Green tape: Used for oxygen lines; grease-free and non-combustible around oxygen
• Gray tape: Used for stainless steel fittings; has a high-density rating, nearly double the thickness of other threading tapes; prevents seizing and galling
  

Safety Considerations

Overuse or misapplication of thread can be hazardous. Do not apply more than six wrappings around a threading. Excess application of tape can prevent the mating of the threads, causing shearing or bursting at the threads.

Overheating the threading or Teflon at high temperatures in industrial applications can produce perfluoroisobutene, a toxic and potentially fatal gas.

Instructions for Using Plumbers (Teflon) Tape

The trick to applying Teflon tape correctly is wrapping it around the pipe correctly. When the pipe is turned into the fitting, the friction of the mating threads should work to tighten the tape around the pipe rather than work against it and unravel or ball up the tape.

Wrap the tape around the pipe in the same clockwise direction as how the pipe will turn into the fitting. This way, it won't unravel while making up the joint.

1. Clean the Pipe

   Clean the male threads at the end of the pipe with a clean rag.

   The Spruce / Kevin Norris

2. Line Up the Pipe and Tape

   Place the end of the plumber's tape on the second thread from the end of the pipe and hold it in place with a finger or thumb. The tape should lie flat (not bunched up) over the threads and extend perpendicularly to the length of the pipe.

   The Spruce / Kevin Norris

3. Wrap the Tape

   Begin wrapping the tape around the pipe in the same direction as the direction the pipe will be turned.

   The Spruce / Kevin Norris

4. Keep the Tape Tight

   Maintain tension on the tape so it wraps snugly around the pipe. Work away from the end of the pipe, overlapping the tape as you go.

   The Spruce / Kevin Norris

5. Wrap 4 to 6 Times

   Complete four to six wraps around the pipe, finishing near the end of the threads (opposite the end of the pipe).

   The Spruce / Kevin Norris

6. Break the Tape

   Break the tape from the roll by gripping it between the thumb and forefinger and pulling sharply; it breaks easily. Smooth the loose end down over the threads. The pipe is now ready to go into the fitting.

   The Spruce / Kevin Norris

When to Use Plumber's (Teflon) Tape

Common places to use plumber's tape include:

• Shower arms
• Showerheads
• Threaded tub spouts
• Pipe-to-coupling connections
• Pipe-to-valve connections

If you're familiar with using pipe-joint compound (pipe dope), you can substitute it with a plumber's tape in the same applications. It can be used on all standard metal and rigid plastic pipe materials.

When Not to Use Plumber's (Teflon) Tape

Using plumber's tape on PVC, copper, or PEX pipe threading is usually not recommended. Those fittings often have a gasket or O-ring to create a seal between the two pipes. Also, avoid using this threading tape on fluid power (hydraulic) systems.

Teflon tape is recommended for brass fittings except for when it comes with a rubber gasket. Also, never use Teflon tape under brass's compression nut flare threads or any other compression fitting type.

Also, if you're using another type of threading sealant, like pipe dope compound, never use it with Teflon tape. Using both can overload the threads and affect the seal.

How Often to Replace Plumber's (Teflon) Tape

Teflon tape is considered a single-use item, meaning once you've applied it, that same tape can't be used again. However, it lasts long, usually many years. If you unthread the fitting for any reason, you will need to remove the used tape and reapply a new wrapping.