- This page provided the thread dimensions of 3/4 - 14 NPTF
- NPTF stands for National Pipe Thread Fuel, based on ASTM B1.20.3.
- It is also called Dryseal Pipe Thread.
- It is a variation of the more popular NPT thread standard based on ASTM B1.20.1.
- Learn more about NPTF and the difference between NPTF and NPT
3/4 - 14 NPTF - External Basic Thread Dimensions
For interpertations of the terms scroll down to the drawings below the table
| Property | Inch | mm |
|---|---|---|
| Nominal Pipe Size(∅) | 3/4 | |
| Pipe Outside Diameter (D) | 1.05 | 26.67 |
| Fitting Outside Diameter (D2) | 1.06 | 26.92 |
| Pitch - TPI (P) | 14 | ... |
| Pitch - Distance (P) | 0.071429 | 1.8143 |
| Thread Tapper Angle (β) | 1.7893 ° | |
| Thread V half Angle (α) | 30 ° | |
| Height of sharp V (H) | 0.061800 | 1.57 |
| Thread Height (h) | 0.05315 | 1.35 |
| Root Truncation (fr) | 0.0052 | 0.132 |
| Crest Truncation (fc) | 0.00345 | 0.088 |
| End of Thread Pitch Diameter (E0) | 0.96768 | 24.579 |
| Hand-Tight Engagement Length (L1) | 0.33900 | 8.611 |
| Pitch Diameter at L1 plane (E1) | 0.98887 | 25.117 |
| Length of Last usefull Thread (L2) | 0.54570 | 13.861 |
| Pitch Diameter at L2 plane (E2) | 1.00179 | 25.445 |
| Overall Thread Length (L2 + 3P) | 0.75000 | 19.05 |
| Length of Vanish threads (V) | 0.20430 | 5.189 |
3/4 - 14 NPTF - External Thread Drawing
Overview Drawing
Profile Drawing
3/4 - 14 NPTF - Internal Basic Thread Dimensions
For interpertations of the terms scroll down to the drawings below the table
| Property | Inch | mm |
|---|---|---|
| Nominal Pipe Size(∅) | 3/4 | |
| Pitch - TPI (P) | 14 | ... |
| Pitch - Distance (P) | 0.071429 | 1.8143 |
| Thread Tapper Angle (β) | 1.7893 ° | |
| Thread V half Angle (α) | 30 ° | |
| Height of sharp V (H) | 1.0600 | 1.814 |
| Thread Height (h) | 0.05315 | 1.35 |
| Root Truncation (fr) | 0.0052 | 0.132 |
| Crest Truncation (fc) | 0.00345 | 0.088 |
| Pitch Diameter at the end of the thread (E1) | 0.98887 | 25.117 |
| Hand-Tight Engagement Length (L1) | 0.33900 | 8.611 |
| Length of Wrenching Allowance (L3) | 0.21430 | 5.443 |
| Pitch Diameter at L3 plane (E3) | 0.95430 | 24.239 |
| Ideal Tap Drill Size | 0.90670 | 23.03 |
| Nearest standard Inch drill | 29 / 32 (0,906) |
3/4 - 14 NPTF - Internal Thread Drawing
Overview Drawing
Profile Drawing
3/4 - 14 NPTF - Tolerances
| Property | Minimum | Maximum |
|---|---|---|
| Thread Height (h) | 0.051400" (1.306 mm) | 0.054900" (1.394 mm) |
| Root Truncation (fr) | 0.00430" (0.109 mm) | 0.00610" (0.155 mm) |
| Crest Truncation (fc) | 0.00260" (0.066 mm) | 0.00430" (0.109 mm) |
| Tapper Angle (β) | 1.643° | 1.934° |
| Thread Head half Angle (α) | 28° | 32° |
* All other dimensions can be controlled only with gauges.
