This Schedule 80 steel pipe dimensions chart lists standard pipe sizes from NPS 1/8 to NPS 24, including nominal pipe size (NPS), DN, outside diameter (OD), wall thickness and approximate inside diameter (ID) in inches and millimeters.
Use the chart to check Schedule 80 steel pipe sizes, compare dimensions and confirm requirements before purchasing. The dimensional reference for carbon and alloy steel pipe is ASME B36.10M.
Schedule 80 Steel Pipe Dimensions and Sizes
The table below provides the standard Schedule 80 steel pipe dimensions for common nominal pipe sizes. It includes Schedule 80 steel pipe dimensions in mm and inches, along with the corresponding outside diameter, wall thickness and inside diameter.
| NPS (in) | DN | Outside Diameter (in) | Outside Diameter (mm) | Wall Thickness (in) | Wall Thickness (mm) | Approx. Inside Diameter (in) | Approx. Inside Diameter (mm) |
|---|---|---|---|---|---|---|---|
| 1/8 | 6 | 0.405 | 10.3 | 0.095 | 2.41 | 0.215 | 5.46 |
| 1/4 | 8 | 0.540 | 13.7 | 0.119 | 3.02 | 0.302 | 7.67 |
| 3/8 | 10 | 0.675 | 17.1 | 0.126 | 3.20 | 0.423 | 10.74 |
| 1/2 | 15 | 0.840 | 21.3 | 0.147 | 3.73 | 0.546 | 13.84 |
| 3/4 | 20 | 1.050 | 26.7 | 0.154 | 3.91 | 0.742 | 18.85 |
| 1 | 25 | 1.315 | 33.4 | 0.179 | 4.55 | 0.957 | 24.31 |
| 1 1/4 | 32 | 1.660 | 42.2 | 0.191 | 4.85 | 1.278 | 32.46 |
| 1 1/2 | 40 | 1.900 | 48.3 | 0.200 | 5.08 | 1.500 | 38.10 |
| 2 | 50 | 2.375 | 60.3 | 0.218 | 5.54 | 1.939 | 49.25 |
| 2 1/2 | 65 | 2.875 | 73.0 | 0.276 | 7.01 | 2.323 | 58.98 |
| 3 | 80 | 3.500 | 88.9 | 0.300 | 7.62 | 2.900 | 73.66 |
| 3 1/2 | 90 | 4.000 | 101.6 | 0.318 | 8.08 | 3.364 | 85.45 |
| 4 | 100 | 4.500 | 114.3 | 0.337 | 8.56 | 3.826 | 97.18 |
| 5 | 125 | 5.563 | 141.3 | 0.375 | 9.53 | 4.813 | 122.25 |
| 6 | 150 | 6.625 | 168.3 | 0.432 | 10.97 | 5.761 | 146.33 |
| 8 | 200 | 8.625 | 219.1 | 0.500 | 12.70 | 7.625 | 193.68 |
| 10 | 250 | 10.750 | 273.1 | 0.594 | 15.09 | 9.562 | 242.87 |
| 12 | 300 | 12.750 | 323.9 | 0.688 | 17.48 | 11.374 | 288.90 |
| 14 | 350 | 14.000 | 355.6 | 0.750 | 19.05 | 12.500 | 317.50 |
| 16 | 400 | 16.000 | 406.4 | 0.843 | 21.41 | 14.314 | 363.58 |
| 18 | 450 | 18.000 | 457.2 | 0.938 | 23.83 | 16.124 | 409.55 |
| 20 | 500 | 20.000 | 508.0 | 1.031 | 26.19 | 17.938 | 455.63 |
| 24 | 600 | 24.000 | 609.6 | 1.219 | 30.96 | 21.562 | 547.67 |
Note: Dimensions are nominal reference values for carbon and alloy steel pipe under ASME B36.10M. Inside diameter is approximate and calculated from the listed outside diameter and wall thickness. Actual internal dimensions may be affected by manufacturing tolerances.
How to Read Schedule 80 Steel Pipe Dimensions
When checking a Schedule 80 steel pipe chart, distinguish the nominal size from the actual measured diameter. Each dimension serves a different purpose when selecting pipe for a project.
- NPS (Nominal Pipe Size): The standard designation used to identify pipe size. It is not necessarily the actual outside or inside diameter. For example, 2 inch Schedule 80 steel pipe has an outside diameter of 2.375 inches (60.3 mm), not 2 inches.
- DN (Nominal Diameter): The metric designation corresponding approximately to NPS. DN is a nominal size reference rather than a direct measurement.
- Outside Diameter (OD): The external diameter of the pipe. For a given NPS, the standard OD remains the same across different schedules.
- Wall Thickness: The thickness of the pipe wall. The Schedule 80 steel pipe wall thickness depends on the nominal size and is generally greater than that of Schedule 40 pipe of the same NPS.
- Inside Diameter (ID): The approximate internal diameter available for fluid or material flow. It decreases as wall thickness increases.
The approximate inside diameter of Schedule 80 steel pipe can be calculated using:
ID = OD − 2 × Wall Thickness
Use the same unit for all values in the calculation. For instance, the 2-inch size has an OD of 2.375 inches and a wall thickness of 0.218 inches, giving an approximate ID of 1.939 inches.
The Schedule 80 steel pipe wall thickness is generally greater than that of Schedule 40 pipe of the same nominal size. For a side-by-side reference, see our Schedule 40 Steel Pipe Dimensions Chart to compare standard pipe sizes, outside diameters and wall thicknesses.
Schedule 80 Steel Pipe Specifications
In addition to pipe dimensions and wall thickness, confirm the material and supply requirements before placing an order. Schedule 80 identifies a dimensional series; it does not by itself specify the steel grade or guarantee a particular pressure rating.
| Specification | Purchasing Considerations |
|---|---|
| Pipe schedule | Schedule 80 |
| Size range | NPS 1/8–24, subject to availability |
| Dimensional standard | ASME B36.10M for carbon and alloy steel pipe |
| Material | Carbon steel pipe or other specified steel grade |
| Pipe type | Seamless or welded, according to project requirements and applicable standard |
| Length | Standard commercial lengths or specified cut lengths, subject to availability |
| Inspection documents | Mill Test Certificate (MTC) or other documents when required |
| Quantity | Specify size-by-size quantities and total order volume |
Schedule 80 carbon steel pipe is commonly specified where a heavier wall is required. The appropriate grade, manufacturing method and dimensions should be selected according to the applicable piping code and service conditions. Pressure ratings cannot be determined from the schedule number alone; they also depend on material, temperature, design requirements and other relevant factors.
Schedule 80 Steel Pipe Supply
For bulk procurement, provide the required NPS, Schedule 80 wall thickness, steel grade, pipe type, length, quantity and inspection documentation. These details help match the order to project specifications and reduce discrepancies between requested and supplied dimensions.
We support inquiries for steel pipe supply for distributors, fabricators and industrial projects. Share your required sizes and material standards to confirm availability, specifications and delivery arrangements.