ANSI B1.20.1 - NPS - American National Standard Straight Pipe Threads
Dimensions of NPS - American National Standard Straight Pipe Thread - not self-sealing threads are indicated below:
| Pipe Size (inches) | TPI | Pipe Diameter (inches) | Female Thread Inside Diameter (inches) | Tap Drill |
|---|---|---|---|---|
| 1/8 | 27 | 0.405 | 0.34 | S |
| 1/4 | 18 | 0.540 | 0.47 | 29/64 |
| 3/8 | 18 | 0.675 | 0.59 | 19/32 |
| 1/2 | 14 | 0.840 | 0.75 | 47/64 |
| 3/4 | 14 | 1.050 | 0.97 | 15/16 |
| 1 | 11.5 | 1.315 | 1.20 | 1 3/16 |
| 1 1/4 | 11.5 | 1.660 | 1-55 | 1 33/64 |
| 1 1/2 | 11.5 | 1.900 | 1.79 | 1 3/4 |
| 2 | 11.5 | 2.375 | 2.26 | 2 7/32 |
| 2 1/2 | 8 | 2.875 | 2.71 | 2 21/32 |
| 3 | 8 | 3.500 | 3.33 | 3 9/32 |
| 3 1/2 | 8 | 4.000 | 3 25/32 | |
| 4 | 8 | 4.500 | 4 9/32 | |
| 4 1/2 | 8 | 5.000 | 4 25/32 | |
| 5 | 8 | 5.563 | 5 11/32 | |
| 6 | 8 | 6.625 | 6 13/32 |
- 1 inch = 25.4 mm
- TPI - Threads per Inch
- B1.20.1 Standard on Pipe Threads, General Purpose, Inch
Note that both NPT and NPS have the same thread angle, shape, and pitch (threads per inch). However, NPT threads are tapered and NPS threads are straight (parallel). Both threads have a 60° included angle and flat peaks and valleys.
Related Topics
• Dimensions of Pipes and Tubes
Pipe, tube and fittings sizes and dimensions. Inside and outside diameters, weights and more.
• Threads
Thread data - metric, unified, ACME and others.
Related Documents
ANSI B1.20.1 - NPT - American National Standard Taper Pipe Threads
NPT and NPTF pipe threads - dimensions according ANSI/ASME B1.20.1/3.
British Standard Brass Threads
British Brass Thread is an imperial unit based screw thread.
British Standard Cycle Threads
British Standard Cycle is a British Imperial screw thread standard.
BS 21 - Pressure Tight Pipe Thread Joints
BSPT - British Standard Pipe Taper threads & BSP or BSPF - British Standard Pipe Parallel (Straight) threads.
EN 10226 - Pipe Threads where pressure tight joints are made on the threads - Dimensions
Pipe threads where pressure tight joints are made on the threads - Part 1: Taper external threads and parallel internal threads.
ISO 2841 - Spark Plugs Metric Threads
Metric threads spark plugs according ISO 28741.
ISO 7 - Pipe Threads where Pressure-tight Joints are made on the Threads
Pressure-tight joints made on the pipe threads.
ISO 724 - Metric Threads
Dimensions of metric threads according ISO 724.
NPT Threads - Taps and Drill Sizes
NPT - Briggs Standard Pipe threads - Taps and Drill Sizes.
Piping Thread Standards
Applied threaded standards used for piping connections.
Threads commonly used in Piping
Piping thread standards.