How do I measure male and female threads? fpt npt fnpt

Q.  How do I measure pipe and fittings with internal and external threads?

A.

  • For male thread measure the outside diameter of the largest portion of the thread (A). Find the actually inch size closest to what you get for A on the chart below and then to the right of that you will see the pipe size.

    For female thread measure the top of thread at B. Find the actual size closest to the measurement that you get for B and then to the right of that you will see the pipe size.

    Actual size in Inches

    Pipe Thread Size

     

    0.540

    1/4

    0.675

    3/8

    0.840

    1/2

    1.050

    3/4

    1.315

    1

    1.660

    1-1/4

    1.900

    1-1/2

    2.375

    2

    2.875

    2-1/2

    3.5

    3

    4.5

    4

    Article Title:
    How do I measure male and female threads? fpt npt fnpt
    Article Summary:
    Brief description oF measuring internal and external threads.
    Article Date:
    7/9/2003
    Article ID:
    623
    3 user(s) found this article useful. Was this article useful to you?
    Share

    Information disclaimer:

    The information contained in this article is for general information purposes only. The information is provided by United States Plastic Corp. and while we endeavor to keep the information up to date and correct, we make no representations or warranties of any kind, express or implied, about the completeness, accuracy, reliability, suitability or availability with respect to the website or the information, products, services, or related graphics contained on the website for any purpose. Any reliance you place on such information is therefore strictly at your own risk.

    In no event will we be liable for any loss or damage including without limitation, indirect or consequential loss or damage, or any loss or damage whatsoever arising from loss of materials, time or profits arising out of, or in connection with, the use of this information.