This reference is intended for engineers, piping designers, drafters, fabricators, and estimators who need a quick check of Schedule 40 pipe 1/4 inch (DN8) data. Use the dimensional list and table below when coordinating pipe routing, connection details, supports, material takeoffs, and CAD or DWG work.
When reviewing the data, distinguish between the nominal designations NPS 1/4 and DN8 and the measured pipe dimensions. The outside diameter, inside diameter, wall thickness, and weight each serve a different purpose in design and installation decisions.
Schedule 40 pipe 1/4 inch (DN8) is a standard small-bore 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 1/4 Schedule 40 pipe based on ANSI / ASME B36.10, including outside diameter, inside diameter, wall thickness, and weight per meter.
This size is often used in small utility lines, instrumentation piping, low-volume service connections, and fabrication work where accurate dimensional data is important for routing, support selection, material takeoff, and installation planning.
1/4 Inch Schedule 40 Pipe Dimensions
- Nominal Pipe Size (NPS): 1/4 inch
- Diameter Nominal (DN): DN8
- Pipe Schedule: Schedule 40
- Outside Diameter (OD): 13.7 mm
- Wall Thickness: 2.24 mm
- Inside Diameter (ID): 9.22 mm
- Pipe Weight: 0.63 kg/m
- Pipe Weight Including Water: 0.69 kg/m
- Reference Standard: ANSI / ASME B36.10
Schedule 40 Pipe 1/4 Inch (DN8) Data Table
| NPS | DN | OD (mm) | Wall Thickness (mm) | ID (mm) | Weight (kg/m) |
|---|---|---|---|---|---|
| 1/4 inch | DN8 | 13.7 | 2.24 | 9.22 | 0.63 |
What Is 1/4 Inch Schedule 40 Pipe Used For?
1/4 inch Schedule 40 pipe is commonly used in small-bore industrial and utility piping systems where a standardized steel pipe size is required. Engineers, designers, and fabricators often use this size in instrumentation connections, utility piping, compressed air lines, small process piping systems, and light fabrication work.
Because this is a compact pipe size, accurate dimensions and weight data are useful for installation work, support selection, material estimation, and field coordination.
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, and connection layouts. The inside diameter affects internal flow area and small-bore hydraulic calculations. The wall thickness is important for fabrication, welding preparation, and pipe strength, while the pipe weight per meter is useful for support load checks and installation planning.
Using the correct DN8 Schedule 40 pipe dimensions helps reduce drafting errors, procurement mistakes, and field fit-up problems during construction and fabrication work.
1/4 Inch DN8 Schedule 40 Pipe for CAD and Drafting Work
For CAD, BIM, and piping drafting work, this size is commonly listed as NPS 1/4 or DN8. The standard OD of 13.7 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 1/4 inch Schedule 40 pipe dimensions, DN8 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 1/4 inch Schedule 40 pipe?
The outside diameter of 1/4 inch Schedule 40 pipe is 13.7 mm.
What is the wall thickness of DN8 Schedule 40 pipe?
The wall thickness is 2.24 mm.
What is the inside diameter of Schedule 40 pipe 1/4 inch?
The inside diameter is 9.22 mm.
How much does 1/4 inch Schedule 40 pipe weigh?
The pipe weight is 0.63 kg/m. The weight including water is 0.69 kg/m.
Which standard covers these dimensions?
These dimensions are based on ANSI / ASME B36.10.
Conclusion
Schedule 40 pipe 1/4 inch (DN8) is an important reference size for small-bore piping, drafting, fabrication, and engineering calculations. With an OD of 13.7 mm, ID of 9.22 mm, wall thickness of 2.24 mm, and weight of 0.63 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 3/8 inch and 1/2 inch Schedule 40 pipe pages.
How to Read the DN8 Schedule 40 Data
NPS and DN are standardized size designations used to identify the pipe, while the listed outside diameter is the dimension normally coordinated with clamps, supports, sleeves, and connection layouts. The inside diameter is the more relevant reference for internal passage and flow-related checks.
The wall thickness connects the outside and inside dimensions and is important when preparing fabrication details, checking weld fit-up, and reviewing the pipe specification. It should not be treated as a complete pressure or structural design check by itself; service conditions, material requirements, joining details, and applicable project criteria must also be reviewed.
Practical Checks Before Using the Dimensions
- Confirm whether the drawing or procurement document identifies the pipe by NPS, DN, or both.
- Use the outside diameter when coordinating physical clearances and support hardware.
- Use the inside diameter only for calculations where the internal passage is the controlling dimension.
- Use the listed pipe weight for preliminary estimating and support-load coordination, then account for the project conditions required by the design.
- Verify that connected fittings, flanges, valves, tubing, and equipment nozzles use compatible size and specification designations.
Using This Page With CAD and DWG Resources
The downloadable DWG can support drafting workflows, but the model should be checked against the dimensional data and the project’s modeling conventions before issue. Keep the pipe size designation visible in the drawing or component properties so that DN8 is not confused with a different nominal size or with tubing.
For broader coordination, link this reference with the site’s pipe schedule tables, nearby Schedule 40 pipe sizes, pipe fittings and flange dimensions, and piping terminology resources. These related references help users move from a single pipe dimension to a complete piping layout or material takeoff.
Additional Questions About 1/4 Inch Schedule 40 Pipe
Is NPS 1/4 the same designation as DN8?
For this reference size, NPS 1/4 and DN8 identify the same nominal pipe size. They are different designation systems, so drawings and procurement documents should retain the designation required by the project or supplier.
Why is the nominal size not the same as the outside diameter?
Nominal pipe size is an identification convention rather than a direct measurement of the pipe’s outside diameter. For fabrication, routing, and connection coordination, use the dimensional values listed in the table rather than assuming the nominal label is a measured diameter.
What is the difference between pipe weight and weight including water?
Pipe weight refers to the pipe itself, while weight including water adds the listed water-content condition. The two values support different preliminary checks, such as dry material handling versus an operating or filled-line load review.
Can this page be used to select pipe for a pressure system?
It provides dimensional and weight reference data, but pipe selection requires a separate engineering review of service conditions, materials, joining method, design requirements, and applicable project specifications.
Which related references should be checked next?
For adjacent design information, compare nearby Schedule 40 sizes and consult the site’s references for fittings, flanges, pipe schedules, CAD or DWG resources, and piping terminology.