NPS 28 (DN 700) pipe — dimensions and weight
Outside diameter 711.2 mm (28 in), unchanged by schedule. This page lists all 6 tabulated schedules that fit on that diameter, with wall thickness, bore, mass per metre and internal volume.
Nominal pipe size is a label, not a dimension. The outside diameter of NPS 28 is 28 in (711.2 mm), and the bore depends entirely on the wall you choose — 695.4 mm on the thinnest tabulated wall down to 679.4 mm on the heaviest. The naming convention was fixed decades ago so that a fitting size could serve every wall thickness; it is not a measurement, and treating it as one is how a line gets sized off a table for the wrong pipe.
NPS 28 (DN 700) — every tabulated schedule
| Schedule | Wall mm | Inside dia. mm | Metal area mm² | Mass / length | Water capacity L/m |
|---|---|---|---|---|---|
| 10 | 7.92 | 695.4 | 17,509.1 | 137.446 kg/m · 92.360 lb/ft | 379.750 |
| 20 | 12.70 | 685.8 | 27,868.9 | 218.771 kg/m · 147.007 lb/ft | 369.390 |
| 30 | 15.88 | 679.4 | 34,677.8 | 272.221 kg/m · 182.924 lb/ft | 362.581 |
| 40S | 9.52 | 692.1 | 20,996.7 | 164.824 kg/m · 110.757 lb/ft | 376.262 |
| STD | 9.52 | 692.1 | 20,996.7 | 164.824 kg/m · 110.757 lb/ft | 376.262 |
| XS | 12.70 | 685.8 | 27,868.9 | 218.771 kg/m · 147.007 lb/ft | 369.390 |
Wall thicknesses derived from ASME B36.10M / B36.19M. Outside diameter 711.2 mm. Mass computed for Carbon Steel at 7850 kg/m³.
STD and XS are derived rather than tabulated: STD equals Sch 40 up to NPS 10 and is fixed at 0.375 in above it; XS equals Sch 80 up to NPS 8 and is fixed at 0.500 in above. Both appear here as separate rows because both are orderable designations.
How NPS 28 pipe weight is calculated
Schedule 40 is not tabulated at NPS 28. Use the table above for the schedules that are, or the pipe weight calculator with any outside diameter and wall thickness — including non-standard ones.
Internal volume and surface area
Mass is only one of the quantities that fall out of the same geometry. Two others decide real work on a line, and neither appears on a printed pipe chart:
| Wall vs range | Wallmm | Boremm | Masskg/m |
|---|---|---|---|
| 25 % | 0.39 | 710.4 | 6.84 |
| 50 % | 0.47 | 710.3 | 8.21 |
| 100 % | 0.63 | 709.9 | 10.95 |
| 200 % | 0.94 | 709.3 | 16.43 |
| 500 % | 1.88 | 707.4 | 32.83 |
| 1,000 % | 3.44 | 704.3 | 60.08 |
Sampled across the lightest to heaviest tabulated wall at this size. Mass rises roughly linearly with wall while the bore falls, which is the trade-off a schedule choice actually represents.
Download this size
NPS 28 pipe — CSV
Exports the schedule table above. The full pipe dataset, every size against every schedule, is on the downloads page.
Frequently asked questions
What is the outside diameter of NPS 28 pipe?
NPS 28 pipe has an outside diameter of 711.2 mm (28 in), and that diameter is fixed for every schedule at this size. Nominal pipe size is a label, not a dimension: NPS 28 does not measure 28 inches anywhere. The naming convention was chosen so that the outside diameter stays constant while the wall varies.
How much does NPS 28 pipe weigh?
Schedule 40 is not tabulated at this size. Not every schedule is tabulated for this size.
How many schedules are available for NPS 28?
This page lists 6 tabulated schedules, including the derived STD and XS walls. Note that STD and Sch 40 are the same thickness at the small sizes and different from NPS 12 upward, and XS and Sch 80 are the same up to NPS 8 and different above — the two confusions that most often produce a wrong order.
What is the internal diameter of NPS 28 pipe?
The bore is the outside diameter minus twice the wall thickness. The table above gives it for every tabulated schedule at this size.
Nearby nominal sizes
Adjacent sizes in the NPS series. Outside diameters step non-uniformly — the jump from NPS 14 to NPS 16 is 2 in, the same as from NPS 2 to NPS 4.
- NPS 22 (DN 550) — 15 schedules
- NPS 24 (DN 600) — 16 schedules
- NPS 26 (DN 650) — 5 schedules
- NPS 30 (DN 750) — 8 schedules
- NPS 32 (DN 800) — 7 schedules
- NPS 34 (DN 850) — 7 schedules
Schedules at this size
Each schedule page lists every size that carries that wall.
- Sch 10 pipe — 7.92 mm wall here
- Sch 20 pipe — 12.70 mm wall here
- Sch 30 pipe — 15.88 mm wall here
- Sch 40S pipe — 9.52 mm wall here
- STD (Standard) pipe — 9.52 mm wall here
- XS (Extra Strong) pipe — 12.70 mm wall here
Pipe reference and tools
- Pipe overview — schedules, sizes and how weight is computed
- All pipe schedules — Sch 5S to XXS
- All nominal sizes — NPS 1/8 to NPS 36
- DN to NPS conversion — metric to imperial designations
- Pipe weight formula — worked derivation
- Pipe weight calculator — any OD and wall
- All calculators — metal weight and pipe weight
- Download the data — CSV, generated from the same source
- Cross-reference tables — DN / NPS / material equivalents
- Methodology and sources — where every number comes from
Outside diameter for NPS 28 is the standard's governed value of 28 in, converted at exactly 25.4 mm per inch. Wall thicknesses are the tabulated B36.10M / B36.19M values. Mass, bore, internal volume and surface areas are computed on this page.
- ASME B36.10M — Welded and Seamless Wrought Steel Pipe (dimensional tables).
- ASME B36.19M — Stainless Steel Pipe (dimensional tables).
- BIPM / NIST definitional constants: international inch = 25.4 mm, foot = 0.3048 m, pound = 0.45359237 kg.
Dataset version 2026.09.1 · dimensions last verified against source 2026-09-21. Found an error? Report it — corrections are issued with a version bump.