Schedule 20 Pipe Dimensions
Wall thickness, bore and plain-end weight for all 15 sizes ASME B36.10M publishes in schedule 20, NPS 8 through NPS 36.
- Schedule
- Schedule 20
- Sizes published
- 15 (NPS 8 to NPS 36)
- Thinnest wall
- 0.250 in (6.3 mm) at NPS 8
- Thickest wall
- 0.500 in (12.7 mm) at NPS 26
- 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 8 | DN 200 | 8.625219.07 mm | 0.2506.35 mm | 8.125206.38 mm | 22.3633.28 kg/m | 2.693 | detail → |
| NPS 10 | DN 250 | 10.750273.05 mm | 0.2506.35 mm | 10.250260.35 mm | 28.0441.72 kg/m | 4.287 | detail → |
| NPS 12 | DN 300 | 12.750323.85 mm | 0.2506.35 mm | 12.250311.15 mm | 33.3849.67 kg/m | 6.123 | detail → |
| NPS 14 | DN 350 | 14.000355.60 mm | 0.3127.92 mm | 13.376339.75 mm | 45.6167.88 kg/m | 7.300 | detail → |
| NPS 16 | DN 400 | 16.000406.40 mm | 0.3127.92 mm | 15.376390.55 mm | 52.2877.79 kg/m | 9.646 | detail → |
| NPS 18 | DN 450 | 18.000457.20 mm | 0.3127.92 mm | 17.376441.35 mm | 58.9487.71 kg/m | 12.319 | detail → |
| NPS 20 | DN 500 | 20.000508.00 mm | 0.3759.52 mm | 19.250488.95 mm | 78.60116.97 kg/m | 15.119 | detail → |
| NPS 22 | DN 550 | 22.000558.80 mm | 0.3759.52 mm | 21.250539.75 mm | 86.61128.89 kg/m | 18.424 | detail → |
| NPS 24 | DN 600 | 24.000609.60 mm | 0.3759.52 mm | 23.250590.55 mm | 94.62140.81 kg/m | 22.055 | detail → |
| NPS 26 | DN 650 | 26.000660.40 mm | 0.50012.70 mm | 25.000635.00 mm | 136.17202.65 kg/m | 25.500 | detail → |
| NPS 28 | DN 700 | 28.000711.20 mm | 0.50012.70 mm | 27.000685.80 mm | 146.85218.54 kg/m | 29.743 | detail → |
| NPS 30 | DN 750 | 30.000762.00 mm | 0.50012.70 mm | 29.000736.60 mm | 157.53234.43 kg/m | 34.313 | detail → |
| NPS 32 | DN 800 | 32.000812.80 mm | 0.50012.70 mm | 31.000787.40 mm | 168.21250.33 kg/m | 39.209 | detail → |
| NPS 34 | DN 850 | 34.000863.60 mm | 0.50012.70 mm | 33.000838.20 mm | 178.89266.22 kg/m | 44.431 | detail → |
| NPS 36 | DN 900 | 36.000914.40 mm | 0.50012.70 mm | 35.000889.00 mm | 189.57282.12 kg/m | 49.980 | detail → |
Weight is plain-end carbon steel, w = 10.6802 × t × (OD − t) lb/ft.
In this schedule the wall thickness coincides with STD in NPS 20 through NPS 24 and XS in NPS 26 through NPS 36. Outside those sizes it does not, so never substitute one designation for the other without checking the number.
Common questions
What sizes is schedule 20 pipe made in?
ASME B36.10M publishes schedule 20 in 15 sizes, from NPS 8 through NPS 36. Wall thickness runs from 0.250 in (6.3 mm) at the small end to 0.500 in (12.7 mm) at the large end.
Does schedule 20 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.