This reference brings together the dimensional and weight information commonly needed when identifying 1 inch Schedule 5 pipe on piping drawings, material lists, and fabrication documents. It covers the NPS and DN designations, dimensional terms, and the difference between an outside-diameter reference and an internal-flow reference.
Use the table below as a quick dimensional lookup, then confirm the project specification, material, joining method, and service requirements before preparing a fabrication or procurement package. For drawing work, the accompanying DWG resource can also help with preliminary layout and coordination.
Schedule 5 Pipe 1 Inch (DN25) is a steel pipe size commonly used in industrial piping systems that require good flow capacity with a relatively light wall thickness. This pipe size is often used in utility piping, water systems, low-pressure industrial service, and general steel pipe fabrication work.
This dimension data is based on ANSI/ASME B36.10, which is the standard commonly used for carbon steel pipe dimensions.
1 Inch Schedule 5 Pipe Dimensions
- Pipe Schedule: 5
- Nominal Pipe Size: 1 Inch
- DN Size: DN25
- Outside Diameter (OD): 33.4 mm
- Inside Diameter (ID): 30.1 mm
- Wall Thickness: 1.65 mm
- Pipe Weight: 1.29 kg/m
- Pipe Weight Including Water: 2 kg/m
- Standard: ANSI/ASME B36.10
Schedule 5 Pipe 1 Inch Dimension Table
| Pipe Schedule | NPS (Inch) | DN (mm) | OD (mm) | ID (mm) | Wall Thickness (mm) | Weight (kg/m) |
|---|---|---|---|---|---|---|
| 5 | 1 | 25 | 33.4 | 30.1 | 1.65 | 1.29 |
What Is 1 Inch Schedule 5 Pipe?
A 1 inch Schedule 5 pipe is a steel pipe with a nominal size of 1 inch and a relatively thin wall thickness compared with heavier schedules. For this size, the outside diameter is fixed at 33.4 mm, while the inside diameter is 30.1 mm based on a wall thickness of 1.65 mm.
Schedule 5 pipe is often selected when a project needs good flow capacity, reduced pipe weight, and easier handling compared with thicker wall pipes. It is commonly referenced in steel piping design, drafting, fabrication, and material takeoff work.
Where Is Schedule 5 Pipe 1 Inch Used?
This pipe size is commonly used in applications that need good flow capacity with relatively light wall thickness. Typical uses include:
- Water transfer and distribution systems
- Utility and low-pressure industrial piping
- Process and service lines
- Pipe spool fabrication and layout work
- General steel piping projects
Why Pipe Dimensions Matter
Accurate 1 inch Schedule 5 pipe dimensions are important for piping layout, fabrication, transport planning, support design, and installation work. Engineers and designers often check OD, ID, wall thickness, and weight before selecting supports, fittings, welding details, and handling methods.
The outside diameter is important for matching supports, clamps, and pipe accessories. The inside diameter helps estimate internal flow area and system capacity. The wall thickness affects mechanical strength and specification compliance, while the pipe weight per meter is useful for lifting plans, transport, and structural loading calculations.
1 Inch Schedule 5 Pipe Weight Information
The nominal weight of this pipe size is 1.29 kg/m. When filled with water, the combined weight becomes approximately 2 kg/m. This information is useful for pipe support design, structural coordination, and lifting preparation in piping systems.
Difference Between NPS 1 and DN25
NPS 1 is the inch-based nominal pipe size, while DN25 is the metric designation used in international drawings and specifications. Both terms refer to the same nominal pipe size, and users may search by either inch size or DN format depending on project standards.
Common Search Terms for This Pipe Size
Users may also search for this pipe using related keywords such as 1 inch Schedule 5 pipe dimensions, DN25 Schedule 5 pipe dimensions, 1 inch pipe weight per meter, DN25 pipe dimensions, or DN25 sch 5 pipe dimensions.
Conclusion
Schedule 5 Pipe 1 Inch (DN25) has an outside diameter of 33.4 mm, an inside diameter of 30.1 mm, a wall thickness of 1.65 mm, and a weight of 1.29 kg/m. It is a useful steel pipe reference size for design, drafting, fabrication, and procurement work.
This page provides a quick reference for engineers, drafters, fabricators, and buyers who need reliable 1 inch Schedule 5 pipe dimensions and DN25 pipe dimensions in one place.
How to Read This Pipe Reference
NPS 1 and DN25 are nominal designations rather than direct measurements of the pipe outside diameter. The listed outside diameter is the key reference for checking clearances, clamps, supports, sleeves, and connections to compatible components. The inside diameter is more relevant when reviewing flow passages and internal-area assumptions.
Schedule identifies a wall-thickness classification within the dimensional reference. It should not be treated as a complete pressure rating. Allowable service conditions also depend on material, temperature, corrosion allowance, manufacturing requirements, joining details, and the governing design specification.
Practical Checks Before Using the Data
- Match the NPS, DN, and schedule designation across drawings, bills of material, and purchase documents.
- Use the outside diameter when coordinating supports, clamps, penetrations, insulation clearances, and fitting interfaces.
- Use the listed inside diameter only as the dimensional reference provided here; flow calculations may require additional checks for roughness, fittings, valves, and operating conditions.
- Distinguish bare-pipe weight from the water-filled reference when reviewing support reactions, lifting plans, and transport requirements.
- Confirm the applicable material and piping specification before treating the dimensions as a complete design basis.
Related Pipe Reference Topics
For broader project work, this page can be used alongside the site’s references for pipe schedules, NPS and DN designations, pipe fittings and flanges, and pipe support coordination. A link to the DWG pipe reference resources is especially useful for readers moving from dimensional lookup to preliminary drafting.
Frequently Asked Questions
What is the nominal size of Schedule 5 pipe covered here?
The reference is for NPS 1, also identified as DN25. These are two nominal designations for the same pipe size reference.
What dimensions are listed for 1 inch Schedule 5 pipe?
The source data lists the outside diameter, inside diameter, wall thickness, and pipe weight. These values should be read together with the schedule and nominal-size designations shown in the table.
Is Schedule 5 a pressure rating?
No. Schedule describes a pipe wall-thickness classification in the dimensional reference. A pressure assessment requires the applicable material, design code, temperature, corrosion considerations, manufacturing requirements, and project specification.
Why is the outside diameter important?
Outside diameter is used when coordinating supports, clamps, sleeves, clearances, fittings, and other components that interface with the exterior of the pipe.
What does the water-filled weight represent?
It is the combined reference weight of the pipe and its water contents. It can support preliminary coordination for supports, lifting, and structural review, but project-specific loads should be verified for the actual installation.
Can the DWG file be used for final fabrication?
The DWG resource is useful for reference and preliminary drafting. Final fabrication drawings should be checked against the project specification, connection details, tolerances, material requirements, and the responsible engineer’s design documents.