Sch 140 pipe — dimensions and weight
A very heavy wall used in high-pressure process and power piping; it is where pipe stops competing with fabricated heavy-wall alternatives on cost.
9 sizes carry a tabulated Sch 140 wall, from NPS 8 (219.1 mm OD) to NPS 24 (609.6 mm OD). Weights are computed at 7,850 kg/m³ for carbon steel, so a carbon-steel figure here runs about 0.1 % heavier than a mill chart calculated at a rounded nominal density.
How Sch 140 pipe weight is calculated
A pipe is an annulus, so the metal area is the full circle less the bore:
Mass per unit length
m = π/4 · (D² − d²) · 10⁻⁶ · ρ, d = D − 2t
D is the outside diameter, t the wall thickness, d the resulting bore, ρ the material density in kg/m³ and m the mass in kg per metre of length.
Worked through with the default dimensions:
D = 16.000 in × 25.4 = 406.4 mmt = 1.437 in × 25.4 = 36.50 mmd = D − 2t = 406.4 − 2 × 36.50 = 333.4 mmA = π/4 × (406.4² − 333.4²) = 42,415.5 mm²m = 42,415.5 mm² × 10⁻⁶ × 7,850 kg/m³ = 332.962 kg/m
- D
- Outside diameter — governed by the standard, constant across schedules at a given NPS
- t
- Wall thickness — this is what the schedule designates, 20.62–52.37 mm across the sizes here
- d
- Inside diameter, D − 2t. Flow capacity follows this, not the nominal size
- ρ
- Density, 7,850 kg/m³ for carbon steel
Two consequences worth keeping in mind. First, because the outer diameter is fixed by the standard and the schedule only moves the wall inward, a heavier schedule costs bore rather than gaining outside diameter — the pipe still fits the same fitting, it just carries less. Second, the metal is a small fraction of the whole: at NPS 16 Sch 140 the steel is 32.7 % of the full circle's area, which is why pipe is priced and handled as a hollow product rather than as bar stock.
Sch 140 — complete size table
| Nominal size | Metric size | Outside dia. mm | Wall mm | Inside dia. mm | Mass / length |
|---|---|---|---|---|---|
| NPS 8 | DN 200 | 219.1 | 20.62 | 177.8 | 100.939 kg/m · 67.828 lb/ft |
| NPS 10 | DN 250 | 273.1 | 25.40 | 222.3 | 155.128 kg/m · 104.242 lb/ft |
| NPS 12 | DN 300 | 323.8 | 28.57 | 266.7 | 208.081 kg/m · 139.824 lb/ft |
| NPS 14 | DN 350 | 355.6 | 31.75 | 292.1 | 253.575 kg/m · 170.395 lb/ft |
| NPS 16 | DN 400 | 406.4 | 36.50 | 333.4 | 332.962 kg/m · 223.740 lb/ft |
| NPS 18 | DN 450 | 457.2 | 39.67 | 377.9 | 408.523 kg/m · 274.515 lb/ft |
| NPS 20 | DN 500 | 508.0 | 44.45 | 419.1 | 508.145 kg/m · 341.458 lb/ft |
| NPS 22 | DN 550 | 558.8 | 47.63 | 463.5 | 600.377 kg/m · 403.435 lb/ft |
| NPS 24 | DN 600 | 609.6 | 52.37 | 504.9 | 719.735 kg/m · 483.640 lb/ft |
Outside diameters and wall thicknesses derived from ASME B36.10M / B36.19M. Mass computed at 7850 kg/m³ (Carbon Steel).
Sizes marked with a stainless schedule come from ASME B36.19M and the rest from B36.10M; where the standard groups two schedules in one column (Sch 10S/10 at the small end) both keys carry the same wall so a lookup never has to know about the grouping.
Sch 140 against every other schedule at NPS 6
A single nominal size is the clearest place to see what a schedule actually changes. The outside diameter is the same in every row; only the wall moves.
| Schedule | Wall mm | Inside dia. mm | Metal area mm² | Mass / length | Water capacity L/m |
|---|---|---|---|---|---|
| 5S | 2.77 | 162.7 | 1,439.5 | 11.300 kg/m · 7.594 lb/ft | 20.800 |
| 10S | 3.40 | 161.5 | 1,762.9 | 13.839 kg/m · 9.299 lb/ft | 20.477 |
| 10 | 3.40 | 161.5 | 1,762.9 | 13.839 kg/m · 9.299 lb/ft | 20.477 |
| 40S | 7.11 | 154.1 | 3,600.9 | 28.267 kg/m · 18.994 lb/ft | 18.639 |
| 40 | 7.11 | 154.1 | 3,600.9 | 28.267 kg/m · 18.994 lb/ft | 18.639 |
| STD | 7.11 | 154.1 | 3,600.9 | 28.267 kg/m · 18.994 lb/ft | 18.639 |
| 80S | 10.97 | 146.3 | 5,422.5 | 42.567 kg/m · 28.604 lb/ft | 16.817 |
| 80 | 10.97 | 146.3 | 5,422.5 | 42.567 kg/m · 28.604 lb/ft | 16.817 |
| XS | 10.97 | 146.3 | 5,422.5 | 42.567 kg/m · 28.604 lb/ft | 16.817 |
| 120 | 14.27 | 139.7 | 6,906.2 | 54.214 kg/m · 36.430 lb/ft | 15.333 |
| 160 | 18.26 | 131.7 | 8,606.8 | 67.563 kg/m · 45.400 lb/ft | 13.633 |
| XXS | 21.95 | 124.4 | 10,088.6 | 79.195 kg/m · 53.217 lb/ft | 12.151 |
Wall thicknesses derived from ASME B36.10M / B36.19M. Outside diameter 168.3 mm. Mass computed for Carbon Steel at 7850 kg/m³.
Dimensions and mass, in separately addressable form
The water capacity column above is the internal volume per metre — the figure that sizes a hydrostatic test. It is the clearest illustration of why bore matters more than nominal size: two pipes both sold as NPS 6 can differ by a factor of several in the volume they hold.
V = π/4 · d² × 10⁻⁶ L/m at d in mm — for NPS 16 Sch 140, d = 333.4 mm gives 87.30 L/m, or 87.30 kg of water per metre.
Download this schedule
Sch 140 pipe — CSV
Reads the tables on this page, so the file matches what you see. Every schedule and every size is in the full pipe dataset on the downloads page.
Fields are quoted per RFC 4180 with a UTF-8 byte-order mark, so the π-derived figures and unit symbols survive a round trip through Excel.
Frequently asked questions
What is Sch 140 pipe?
Sch 140 is a wall thickness designation, not a size. It applies across the whole nominal size range — this page lists 9 sizes that carry a tabulated Sch 140 wall. The outside diameter changes with size but stays constant across schedules, which is what lets one fitting size serve every wall thickness.
How much does Sch 140 pipe weigh?
Weight depends on the size as well as the schedule, because a bigger pipe has both a larger circumference and (usually) a thicker wall. For reference: . The full table above gives the figure for every size.
How do I calculate Sch 140 pipe weight per metre?
Use the annulus area: π/4 × (OD² − ID²), where ID = OD − 2 × wall. Multiply the result in mm² by 1e-6 to get m², then by the material density in kg/m³. That is what this page does for every row, which is why the weights here can differ in the fourth significant figure from a printed chart that assumes a nominal steel density.
Is Sch 140 the same as another schedule?
Schedule designations coincide at the small end and diverge at the large end. Schedule 40 and STD are identical up to and including NPS 10, then split. Schedule 80 and XS are identical up to NPS 8, then split. Above NPS 10 a single size commonly carries a dozen schedules, so "6-inch pipe" alone does not specify a weight — and the difference between the lightest and heaviest can be a factor of four.
Other schedules
The schedules most often confused with this one come first.
- Sch 160 pipe — 20 sizes
- Sch 120 pipe — 14 sizes
- XXS pipe — 14 sizes
- Sch 100 pipe — 9 sizes
- Sch 5S pipe — 25 sizes
- Sch 10S pipe — 25 sizes
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 diameters and wall thicknesses are the tabulated ASME B36.10M / B36.19M values, stored in inches as the standards govern them and converted at exactly 25.4 mm per inch. Mass, bore, water capacity and surface areas are computed here — none is copied from the standard, which tabulates dimensions rather than weights.
- ASME B36.10M — Welded and Seamless Wrought Steel Pipe (dimensional tables).
- ASME B36.19M — Stainless Steel Pipe (dimensional tables).
- ASTM material specifications for each grade named in the material entry (A36, A240/A276, B209/B211/B221, B152/B16/B505, B265/B348, A48, B29, D1784, D3350).
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.