NPS 1 Pipe
Outside diameter 1.315″
OD in mm 33.401 mm
NPT thread 1″ NPT (11.5 TPI)
Every NPS 1 pipe has this OD regardless of schedule — the schedule changes only the wall thickness and bore.
Schedules
| Schedule | Wall | Wall mm | Inside diameter | ID mm |
|---|---|---|---|---|
| 40 = STD | 0.133″ | 3.378 | 1.049″ | 26.645 |
| 80 = XS | 0.179″ | 4.547 | 0.957″ | 24.308 |
1″ NPT thread
| Designation | 1″ NPT |
|---|---|
| Threads per inch | 11.5 |
| Recommended tap drill | 1-5/32″ (1.1563″ / 29.369 mm) |
NPT is a tapered thread (3/4″ per foot on diameter) — it seals on the thread flanks with sealant. The size refers to the pipe's nominal size, not any measured thread diameter.