What is NPT size?
As a general “rule of thumb” an NPT thread is approximately 1/4″ (0.25”) larger than its “name.” For a 1/4″ NPT fitting the “nominal” OD is 0.533”. NPT fittings are slightly tapered so the “nominal” diameter is the diameter in the middle of the threaded portion, as measured by the top (crest) of the threads.
What does NPT mean?
NPT is the abbreviation for National Pipe Thread Tapered, which is the U.S. standard for tapered threads used to join pipes and fittings. They were established as a standard by the American National Standard Pipe Thread, commonly referred to as the national pipe thread standards.
What is the metric equivalent to 3 8 NPT?
NPT American Taper Pipe Thread ANSI B 1.20. 1
| Nominal Diameter | Major Diameter mm | Tapping Drill Size mm |
|---|---|---|
| 1/16″ – 27 NPT | 7.895 | 6.00 |
| 1/8″ – 27 NPT | 10.242 | 8.25 |
| 1/4″ – 18 NPT | 13.616 | 10.70 |
| 3/8″ – 18 NPT | 17.055 | 14.10 |
What is the minimum thread size for NPT?
**’ = Truncation from point of thread triangle to flat (not shown in diagram). Minimum = 0.033P for all pitches. See table for maximum. When using L1 gauges to check threads, the thread is within permissible tolerance if the ring gauge face, or plug gauge notch, is +/- 1 turn from being flush with the end of the thread.
What are the dimensions of a NPT pipe?
– NPT Thread taper angle = 1/16 taper = 1 deg. 47 min = 0.75 in./ft . – The angle between the sides of the thread is 60 deg. – Thread Designation: The nominal pipe size, number of threads per inch and the thread series symbol in sequence. Ex: 3/8 – 18 NPT – For additional dimensions, see NPT Pipe Thread Calculator.
What is the thread taper angle in NPT?
– NPT Thread taper angle = 1/16 taper = 1 deg. 47 min = 0.75 in./ft . – The angle between the sides of the thread is 60 deg. – Thread Designation: The nominal pipe size, number of threads per inch and the thread series symbol in sequence. Ex: 3/8 – 18 NPT
How many decimal places are in a NPT thread?
American National Standard Taper Pipe Thread (NPT) Chart Note: The dimensions of the NPT Thread are given to four or five decimal places. While this implies a greater degree of precision than is ordinarily achieved, these dimensions are the basis of gage dimensions and are so expressed for the purpose of eliminating errors in computations.
