Use this reference when you need to identify, model, or estimate 5 inch Schedule 40 pipe in a piping project. The page distinguishes the nominal NPS and DN designations from the pipe’s actual outside and inside dimensions, helping designers, fabricators, estimators, and CAD users apply the tabulated data correctly.
For related design work, compare this entry with the site’s 4 inch Schedule 40 pipe, 6 inch Schedule 40 pipe, pipe schedule, fitting dimension, and flange reference pages. These comparisons are useful when checking route transitions, connected components, and material takeoffs.
Schedule 40 pipe 5 inch (DN125) is a standard steel pipe size commonly used in piping design, fabrication, drafting, and engineering estimation work. This page provides the standard dimensions and weight data for NPS 5 Schedule 40 pipe based on ANSI / ASME B36.10, including outside diameter, inside diameter, wall thickness, and weight per meter.
This size is widely used in industrial piping systems, utility services, water lines, and fabrication projects where accurate dimensional data is important for layout, support design, material takeoff, and installation planning.
5 Inch Schedule 40 Pipe Dimensions
- Nominal Pipe Size (NPS): 5 inch
- Diameter Nominal (DN): DN125
- Pipe Schedule: Schedule 40
- Outside Diameter (OD): 141.3 mm
- Wall Thickness: 6.55 mm
- Inside Diameter (ID): 128.2 mm
- Pipe Weight: 21.77 kg/m
- Pipe Weight Including Water: 34.67 kg/m
- Reference Standard: ANSI / ASME B36.10
Schedule 40 Pipe 5 Inch (DN125) Data Table
| NPS | DN | OD (mm) | Wall Thickness (mm) | ID (mm) | Weight (kg/m) |
|---|---|---|---|---|---|
| 5 inch | DN125 | 141.3 | 6.55 | 128.2 | 21.77 |
What Is 5 Inch Schedule 40 Pipe Used For?
5 inch Schedule 40 pipe is commonly used in industrial and utility piping systems where a standardized steel pipe size is required. Engineers, designers, and fabricators often use this size in:
- Water distribution systems
- Cooling water piping
- Industrial utility lines
- Process piping systems
- Plant layout and pipe routing work
- Fabrication and spool drawing preparation
Because this is a practical mid-size pipe, accurate dimensions and weight data are important for support design, transport planning, installation work, and material estimation.
Why These Dimensions Matter in Engineering
In piping and mechanical design, standard pipe dimensions are important for more than simple identification. The outside diameter is used for supports, clamps, insulation sizing, and equipment connection layouts. The inside diameter affects internal flow area and hydraulic calculations. The wall thickness is important for fabrication, welding preparation, and pipe strength, while the pipe weight per meter is essential for support load calculations and installation planning.
Using the correct DN125 Schedule 40 pipe dimensions helps reduce drafting errors, procurement mistakes, and field fit-up problems during construction and fabrication work.
5 Inch DN125 Schedule 40 Pipe for CAD and Drafting Work
For CAD, BIM, and piping drafting work, this size is commonly listed as NPS 5 or DN125. The standard OD of 141.3 mm is especially useful for routing clearance, support detailing, and nozzle or equipment connection references in both 2D drawings and 3D models.
This page can be used as a quick reference for 5 inch Schedule 40 pipe dimensions, DN125 pipe dimensions, and Schedule 40 steel pipe weight per meter during design, drafting, and estimation work.
Frequently Asked Questions
What is the outside diameter of 5 inch Schedule 40 pipe?
The outside diameter of 5 inch Schedule 40 pipe is 141.3 mm.
What is the wall thickness of DN125 Schedule 40 pipe?
The wall thickness is 6.55 mm.
What is the inside diameter of Schedule 40 pipe 5 inch?
The inside diameter is 128.2 mm.
How much does 5 inch Schedule 40 pipe weigh?
The pipe weight is 21.77 kg/m. The weight including water is 34.67 kg/m.
Which standard covers these dimensions?
These dimensions are based on ANSI / ASME B36.10.
Conclusion
Schedule 40 pipe 5 inch (DN125) is an important reference size for industrial piping, drafting, fabrication, and engineering calculations. With an OD of 141.3 mm, ID of 128.2 mm, wall thickness of 6.55 mm, and weight of 21.77 kg/m, it is a useful standard pipe size for engineers, designers, and estimators working with steel piping systems.
For more pipe schedule data, compare this size with nearby standard sizes such as 4 inch and 6 inch Schedule 40 pipe pages.
How to Read This 5 Inch Schedule 40 Pipe Reference
NPS 5 and DN125 are nominal designations used to identify the pipe size; they should not be treated as a direct measurement of the pipe’s actual diameter. For layout and fabrication, use the listed outside diameter, inside diameter, and wall thickness rather than relying on the nominal name alone.
The schedule identifies a standardized wall-thickness designation for the selected nominal pipe size. It is not, by itself, a material grade, pressure rating, or complete design specification. Procurement and engineering documents should also confirm the applicable material, manufacturing requirements, joining method, service conditions, and project specifications.
Using the Data in Design and Drafting
- Use the outside diameter when checking supports, clamps, insulation space, clearances, and equipment connection layouts.
- Use the inside diameter when performing flow-area or hydraulic checks, subject to the assumptions and tolerances required by the project.
- Use wall thickness for detailing, weld preparation, fabrication review, and verification against the governing design requirements.
- Use the listed mass per unit length for preliminary support, handling, transport, and material-estimating work.
The downloadable DWG can support drafting workflows, but the model should be reviewed against the table before release. Confirm units, layer conventions, connection details, centerline assumptions, and any project-specific tolerances before using the file for fabrication or construction documentation.
Related Pipe Reference Topics
Readers working with this size may also need the site’s pipe schedule chart, steel pipe weight references, pipe fittings dimensions, flange dimensions, and CAD/DWG pipe resources. Linking these topics from this page gives users a practical path from basic pipe identification to routing, connection, and drafting checks.
Practical Questions About 5 Inch Schedule 40 Pipe
Is the nominal size the same as the measured pipe diameter?
No. The NPS and DN labels identify the nominal pipe size. For physical layout, clearance, and connection work, use the tabulated outside and inside dimensions.
Does Schedule 40 alone define whether the pipe is suitable for a service?
No. Schedule identifies the dimensional wall designation for the size. Suitability also depends on material, temperature, pressure, corrosion allowance, joining requirements, applicable design rules, and project specifications.
Which dimension should be used for a pipe support?
Support and clamp geometry generally reference the pipe’s outside diameter, while the support load must account for the pipe, contents, insulation, fittings, and other applicable loads. Final support design requires project-specific engineering review.
Can the DWG be used directly for fabrication?
Use the DWG as a drafting reference and verify it against the published dimensions and the project drawing standard. Check units, connections, tolerances, and fabrication requirements before issuing it for construction.