External (pipe) Basic Thread Dimensions
For interpertations of the terms scroll down to the drawings below the table
| Property | Inch | mm |
|---|---|---|
| Nominal Pipe Size (Ø) | 1/8" | ... |
| Pipe Outside Diameter (D) | 0.405 | 10.287 |
| Pitch (TPI) (P) | 27.000 | 685.8 |
| Pitch (Distance) (P) | 0.03703704 | 0.941 |
| Thread Tapper Angle (ß) | 1.7893° | 1.7893° |
| Thread V half Angle (α) | 30° | 30° |
| Height of sharp V (H) | 0.032075 | 0.815 |
| Thread height (h) | 0.02963 | 0.753 |
| Pitch Diameter at the Pipe's end (E0) | 0.36351 | 9.233 |
| Minor Diameter at the Pipe's end (K0) | 0.3339 | 8.481 |
| Hand-Tight Engagement Length (L1) | 0.1615 | 4.102 |
| Pitch Diameter at L1 plane (E1) | 0.3736 | 9.489 |
| Length of Last Complete Thread (L5) | 0.1898 | 4.821 |
| Pitch Diameter at L5 plane (E5) | 0.37537 | 9.534 |
| Length of Last usefull Thread (L2) | 0.2639 | 6.703 |
| Pitch Diameter at L2 plane (E2) | 0.38 | 9.652 |
| Overall Thread Length (L4) | 0.3924 | 9.967 |
| Length of Vanish threads (V) | 0.1285 | 3.264 |
1/8-27 NPT - External (pipe) Drawing
Overview Drawing
Profile Drawing
1/8-27 NPT - Internal (Fitting) Basic Thread Dimensions
For interpertations of the terms scroll down to the drawings below the table
| Property | Inch | mm |
|---|---|---|
| Nominal Pipe Size (Ø) | 1/8" | ... |
| Pipe Outside Diameter (D) | 0.405 | 10.287 |
| Pitch (TPI) (P) | 27.000 | 685.8 |
| Pitch (Distance) (P) | 0.03703704 | 0.941 |
| Thread Tapper Angle (ß) | 1.7893° | 1.7893° |
| Thread V half Angle (α) | 30° | 30° |
| Height of sharp V (H) | 0.032075 | 0.815 |
| Thread height (h) | 0.02963 | 0.753 |
| Pitch Diameter at the fitting's end (E1) | 0.3736 | 9.489 |
| Length of Hand-Tight Engagemen (L1) | 0.1615 | 4.102 |
Length of Wrenching Allowance (L3) |
0.1111 | 2.822 |
| Pitch Diameter at L3 plane (E3) | 0.35656 | 9.057 |
| Tap Drill Size (T) | 0.332 | 8.433 |
1/8-27 NPT - Internal (Fitting) Drawing
Overview Drawing
Profile Drawing
1/8-27 NPT - Tolerances
| Property | Minimum | Maximum |
|---|---|---|
| Thread Height (h) | 0.02496" (0.634 mm) | 0.02963" (0.753 mm) |
| L1 gage Tolerance (+/- 1 Turn) (L1) | ... | 0.03704" (0.941 mm) |
| Thread Truncation (f) | 0.0012" (0.03 mm) | 0.0036" (0.091 mm) |
| Tapper angle Variation (ß) | 1.641" ( ) | 2.089" ( ) |
| Thead V Half Angle (+/-) (α) | ... | 1.25" ( ) |
| Thread Height (h) | " (0 mm) | " (0 mm) |
| L1 gage Tolerance (+/- 1 Turn) (L1) | " ( ) | " ( ) |
| Thread Truncation (f) | " (0 mm) | " (0 mm) |
| Tapper angle Variation (ß) | " ( ) | " ( ) |
| Thead V Half Angle (+/-) (α) | " ( ) | " ( ) |
