In the piping system, Pipe Thread Chart is an essential tool. By standardizing the size parameters and ensuring the reliability of pipe thread connections, accidents such as leakage caused by thread mismatch can be avoided to the greatest extent, thus improving work efficiency.
Pipe Thread Chart
Pipe Thread Chart is a standardized technical document that contains dimensional parameters (such as major diameter, minor diameter, and pitch), standard specifications (such as NPT, BSP, and Metric), and application scenarios.
The core function of Pipe Thread Chart
- Ensure that the threaded joint matches the pipe thread.
- Guide thread processing
- Assist in troubleshooting
Common pipe thread standards
American Standard
NPT (National Pipe Taper) is a tapered pipe thread with a thread profile of 60 degrees. It is divided into internal threads (NPT-F) and external threads (NPT-M). The internal threads are straight cones and the external threads are tapers.
ASME B1.20.1-2020
|
Thread Size (inches) |
Large diameter (mm) |
Minor diameter (mm) |
Pitch (thread/inch) |
Application Scenario |
|
1/8 |
10.242 |
8.712 |
27 |
Small hydraulic systems, gas pipelines |
|
1/4 |
13.616 |
11.358 |
18 |
家庭 plumbing、低压水管 |
|
1/2 |
21.223 |
18.321 |
14 |
Industrial steam pipelines, oil and gas well pipes |
|
3/4 |
26.568 |
23.117 |
14 |
Large water pumps, compressed air pipelines |
|
1 |
33.249 |
29.692 |
11.5 |
High-pressure oil and gas transmission pipeline |
British Standard
There are two types of BSP, parallel pipe thread (BSPP) and tapered pipe thread (BSPT), with a thread profile of 55°.
ISO 7/1-2013
|
Thread Size (inches) |
type |
Large diameter (mm) |
Minor diameter (mm) |
Pitch (thread/inch) |
Application Scenario |
|
1/8 |
BSPP |
9.728 |
8.566 |
28 |
Household faucets and bathroom pipes |
|
1/4 |
BSPT |
13.157 |
11.445 |
19 |
Hydraulic equipment, small compressors |
|
1/2 |
BSPP |
20.955 |
18.631 |
14 |
Industrial cooling water pipes, ventilation systems |
|
3/4 |
BSPT |
26.441 |
23.527 |
14 |
Natural gas transmission pipelines, boiler systems |
|
1 |
BSPP |
33.249 |
30.291 |
11 |
Large water supply pipelines, fire protection systems |
Metric standard
Metric pipe threads (such as M20×1.5) use metric dimensions (diameter×pitch) and have a thread profile of 60°.
ISO 228-1-2019
|
Thread size (mm) |
Large diameter (mm) |
Minor diameter (mm) |
Pitch (mm) |
Application Scenario |
|
M10×1.0 |
10.000 |
8.376 |
1.0 |
Small instrument and electronic equipment pipeline |
|
M16×1.5 |
16.000 |
13.835 |
1.5 |
Industrial hydraulic pipelines, cooling systems |
|
M20×1.5 |
20.000 |
17.835 |
1.5 |
Building water supply pipelines, fire fighting equipment |
|
M27×2.0 |
27.000 |
24.113 |
2.0 |
Large industrial pipelines, oil and gas transmission |
FAQs
1.What threads should be used for steam and hydraulic oil pipelines (high pressure and high temperature)?
Preferably, tapered sealing threads (such as NPT or BSPT) should be used.
2.What threads should be used for high pressure (>10bar) and low pressure (≤10bar)?
High pressure uses tapered threads (NPT, BSPT), and low pressure uses parallel threads (BSPP, Metric).
