ISO Threads
Reference data and engineering information about iso threads for standard organizations applications.
isothreads
Overview
Engineering reference data for ISO Threads in standard organizations.
Key Formulas
ISO Standard
Quality management systems.
ASTM Standard
Standard test methods for tension testing.
ANSI Standard
Pipe flanges and flanged fittings.
Variables
| Symbol | Description | Unit |
|---|---|---|
| International Organization for Standardization | — | |
| American Society for Testing and Materials | — | |
| American National Standards Institute | — |
Thread Dimensions and Tolerances
9 rows
Pipe Size (inches) | Threads per Inch (TPI) | Lead (mm) | Outside Diameter (mm) | Pitch Diameter (mm) | Minor Diameter (mm) | Rp/Rc R | a (mm) | Internal Thread Tolerance (mm) | Internal Thread Tolerance (turns) | External Thread Tolerance (turns) | External Thread Tolerance (mm) |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1/16 | 28 | 0.907 | 7.723 | 7.142 | 6.561 | 1/16 | 4 | ± 0.071 | ± 1 1/4 | ± 1 | ± 0.9 |
| 1/8 | 28 | 0.907 | 9.23 | 9.147 | 8.566 | 1/8 | 4 | ± 0.071 | ± 1 1/4 | ± 1 | ± 0.9 |
| 1/4 | 19 | 1.337 | 13.157 | 12.301 | 11.445 | 1/4 | 6 | ± 0.104 | ± 1 1/4 | ± 1 | ± 1.3 |
| 3/8 | 19 | 1.337 | 16.662 | 15.806 | 14.95 | 3/8 | 6.4 | ± 0.104 | ± 1 1/4 | ± 1 | ± 1.3 |
| 1/2 | 14 | 1.814 | 20.955 | 19.793 | 18.631 | 1/2 | 8.2 | ± 0.142 | ± 1 1/4 | ± 1 | ± 1.8 |
| 3/4 | 14 | 1.814 | 26.441 | 25.279 | 24.117 | 3/4 | 9.5 | ± 0.142 | ± 1 1/4 | ± 1 | ± 1.8 |
| 1 | 11 | 2.309 | 33.249 | 31.77 | 30.291 | 1 | 10.4 | ± 0.18 | ± 1 1/4 | ± 1 | ± 2.3 |
| 1 1/4 | 11 | 2.309 | 41.91 | 40.431 | 38.952 | 1 1/4 | 12.7 | ± 0.18 | ± 1 1/4 | ± 1 | ± 2.3 |
| 1 1/2 | 11 | 2.309 | 47.803 | 46.324 | 44.845 | 1 1/2 | 12.7 | ± 0.18 | ± 1 1/4 | ± 1 | ± 2.3 |
Source: engineeringtoolbox.com