NPS 1/4 Pipe Dimensions
Outside diameter 0.540 in (13.7 mm) — fixed across every schedule. 6 wall thicknesses from ASME B36.10M, with bore, plain-end weight and flow area for each.
- Nominal size
- NPS 1/4
- Metric designator
- DN 8
- Outside diameter
- 0.540 in (13.7 mm)
- Schedules listed
- 6
- Standard weight wall
- 0.088 in (2.2 mm)
- Extra strong wall
- 0.119 in (3.0 mm)
Every schedule in NPS 1/4
Dimensions are given in inches, with the millimetre equivalent beneath in grey.
| Schedule | Wall thickness | Inside diameter | Weight, empty | Flow area (in²) | Water (US gal/ft) |
|---|---|---|---|---|---|
| Sch 5 | 0.0491.24 mm | 0.44211.23 mm | 0.260.38 kg/m | 0.15 | 0.008 |
| Sch 10 | 0.0651.65 mm | 0.41010.41 mm | 0.330.49 kg/m | 0.13 | 0.007 |
| Sch 40 | 0.0882.24 mm | 0.3649.25 mm | 0.420.63 kg/m | 0.10 | 0.005 |
| STD | 0.0882.24 mm | 0.3649.25 mm | 0.420.63 kg/m | 0.10 | 0.005 |
| Sch 80 | 0.1193.02 mm | 0.3027.67 mm | 0.540.80 kg/m | 0.07 | 0.004 |
| XS | 0.1193.02 mm | 0.3027.67 mm | 0.540.80 kg/m | 0.07 | 0.004 |
Weight is calculated for carbon steel as w = 10.6802 × t × (OD − t) lb/ft and is the plain-end weight, excluding coatings, linings and fittings.
Standard weight equals Schedule 40 in this size. Extra strong equals Schedule 80.
This size, schedule by schedule
A page for each combination, with bore, weight, water capacity and the matching flange and fitting data.
This size in a schedule chart
Common questions
What is the outside diameter of NPS 1/4 pipe?
NPS 1/4 pipe has an outside diameter of 0.540 in (13.7 mm). That outside diameter is fixed: it is identical in every schedule, and only the wall thickness — and therefore the bore — changes from one schedule to the next.
How much does NPS 1/4 schedule 40 pipe weigh?
0.42 lb/ft (0.63 kg/m) as plain-end carbon steel, on a wall thickness of 0.088 in (2.2 mm).
What is the metric equivalent of NPS 1/4?
DN 8. DN is a dimensionless designator, not a measurement — DN 8 pipe does not measure 8 mm anywhere. Its actual outside diameter is 13.7 mm.