Schedule 120 Pipe Dimensions
Wall thickness, bore and plain-end weight for all 12 sizes ASME B36.10M publishes in schedule 120, NPS 4 through NPS 24.
- Schedule
- Schedule 120
- Sizes published
- 12 (NPS 4 to NPS 24)
- Thinnest wall
- 0.438 in (11.1 mm) at NPS 4
- Thickest wall
- 1.812 in (46.0 mm) at NPS 24
- Standard
- ASME B36.10M
Dimensions are given in inches, with the millimetre equivalent beneath in grey.
| Size | DN | Outside diameter | Wall thickness | Inside diameter | Weight, empty | Water (US gal/ft) | This size |
|---|---|---|---|---|---|---|---|
| NPS 4 | DN 100 | 4.500114.30 mm | 0.43811.13 mm | 3.62492.05 mm | 19.0028.28 kg/m | 0.536 | detail → |
| NPS 5 | DN 125 | 5.563141.30 mm | 0.50012.70 mm | 4.563115.90 mm | 27.0440.24 kg/m | 0.849 | detail → |
| NPS 6 | DN 150 | 6.625168.27 mm | 0.56214.27 mm | 5.501139.73 mm | 36.3954.16 kg/m | 1.235 | detail → |
| NPS 8 | DN 200 | 8.625219.07 mm | 0.71918.26 mm | 7.187182.55 mm | 60.7190.35 kg/m | 2.107 | detail → |
| NPS 10 | DN 250 | 10.750273.05 mm | 0.84421.44 mm | 9.062230.17 mm | 89.29132.88 kg/m | 3.350 | detail → |
| NPS 12 | DN 300 | 12.750323.85 mm | 1.00025.40 mm | 10.750273.05 mm | 125.49186.75 kg/m | 4.715 | detail → |
| NPS 14 | DN 350 | 14.000355.60 mm | 1.09427.79 mm | 11.812300.02 mm | 150.80224.41 kg/m | 5.693 | detail → |
| NPS 16 | DN 400 | 16.000406.40 mm | 1.21930.96 mm | 13.562344.47 mm | 192.44286.38 kg/m | 7.504 | detail → |
| NPS 18 | DN 450 | 18.000457.20 mm | 1.37534.92 mm | 15.250387.35 mm | 244.14363.32 kg/m | 9.489 | detail → |
| NPS 20 | DN 500 | 20.000508.00 mm | 1.50038.10 mm | 17.000431.80 mm | 296.38441.05 kg/m | 11.791 | detail → |
| NPS 22 | DN 550 | 22.000558.80 mm | 1.62541.27 mm | 18.750476.25 mm | 353.61526.24 kg/m | 14.344 | detail → |
| NPS 24 | DN 600 | 24.000609.60 mm | 1.81246.02 mm | 20.376517.55 mm | 429.39639.01 kg/m | 16.939 | detail → |
Weight is plain-end carbon steel, w = 10.6802 × t × (OD − t) lb/ft.
In this schedule the wall thickness coincides with XXS in NPS 12. Outside those sizes it does not, so never substitute one designation for the other without checking the number.
Common questions
What sizes is schedule 120 pipe made in?
ASME B36.10M publishes schedule 120 in 12 sizes, from NPS 4 through NPS 24. Wall thickness runs from 0.438 in (11.1 mm) at the small end to 1.812 in (46.0 mm) at the large end.
Does schedule 120 mean the same wall thickness in every size?
No. A schedule number is a series, not a thickness. It sets a wall that rises with the pipe size so the pressure rating stays roughly constant across the range — which is the whole point of the schedule system.