Use this page as a quick reference when checking 1 inch Schedule 160 pipe dimensions for piping layouts, material takeoffs, fabrication drawings, and engineering estimates. The source table gives the controlling local values for outside diameter, wall thickness, inside diameter, and weight.
For related design work, compare this entry with the site’s pipe schedule reference, NPS and DN terminology guide, and pipe weight references. Drafting teams can also use the available Schedule 160 pipe DWG when developing or reviewing CAD layouts.
Schedule 160 pipe 1 inch (DN25) is an extra heavy-wall steel pipe size commonly used in piping design, fabrication, drafting, and engineering estimation work. This page provides the standard dimensions, wall thickness, inside diameter, and weight per meter for NPS 1 Schedule 160 pipe based on ASME B36.10.
1 Inch Schedule 160 Pipe Dimensions
- Nominal Pipe Size (NPS): 1 inch
- Diameter Nominal (DN): DN25
- Outside Diameter (OD): 33.4 mm
- Wall Thickness: 6.35 mm
- Inside Diameter (ID): 20.7 mm
- Pipe Weight: 4.24 kg/m
- Pipe Weight Filled With Water: 4.57 kg/m
- Reference Standard: ASME B36.10
- Pipe Type: Steel Pipe
Schedule 160 Pipe 1 Inch Data Table
| Pipe Size | DN | OD (mm) | Wall Thickness (mm) | ID (mm) | Weight (kg/m) |
|---|---|---|---|---|---|
| 1 inch | 25 | 33.4 | 6.35 | 20.7 | 4.24 |
What Does Schedule 160 Mean?
Schedule 160 refers to an extra heavy wall thickness series used for steel pipe under ASME B36.10. For the same nominal pipe size, the outside diameter remains fixed while the wall thickness increases according to the schedule. A much thicker wall reduces the inside diameter and significantly increases pipe weight.
Typical Uses of 1 Inch Schedule 160 Pipe
NPS 1 Schedule 160 pipe is commonly referenced for very heavy-duty industrial piping systems where extremely high wall thickness is required. It may be used in process piping, plant utility systems, structural loading checks, fabrication work, and engineering applications where pipe strength and wall thickness are more critical than maximum flow area.
Why Pipe Weight Matters
Pipe weight per meter is essential for transport planning, lifting studies, support design, structural loading, fabrication estimates, and installation planning. For a 1 inch Schedule 160 pipe, the extra heavy wall thickness results in much higher installed weight than lighter schedules, so accurate weight data is important for engineering and construction work.
1 Inch Schedule 160 Pipe Calculation Notes
The listed weight is based on standard steel pipe dimensions using the outside diameter and wall thickness of the pipe. Actual product weight may vary slightly depending on manufacturing tolerance, material specification, and supplier standard.
Frequently Asked Questions
What is the outside diameter of 1 inch Schedule 160 pipe?
The outside diameter is 33.4 mm.
What is the wall thickness of DN25 Schedule 160 pipe?
The wall thickness is 6.35 mm.
What is the inside diameter of NPS 1 Schedule 160 pipe?
The inside diameter is 20.7 mm.
How much does 1 inch Schedule 160 pipe weigh?
The approximate weight is 4.24 kg/m.
Which standard covers this pipe size?
This dimension data is based on ASME B36.10 for steel pipe.
Conclusion
Schedule 160 pipe 1 inch (DN25) has an outside diameter of 33.4 mm, wall thickness of 6.35 mm, inside diameter of 20.7 mm, and a weight of 4.24 kg/m. It is a useful reference for piping design, fabrication, estimating, and heavy-duty industrial engineering work.
How to Use This Schedule 160 Pipe Reference
Start with the nominal designation: NPS 1 and DN25 identify the same nominal pipe size in the source data. Nominal size should not be treated as a direct measurement of the actual outside or inside diameter; use the listed OD, wall thickness, and ID when preparing drawings or checking clearances.
Dimension checks for drafting
The outside diameter is useful for checking supports, clamps, penetrations, and connection geometry. The wall thickness and inside diameter are more relevant when reviewing bore clearance, component fit-up, and the available flow passage. Because the schedule changes the wall thickness within a nominal size, do not infer the inside diameter from the nominal designation alone.
Weight and installation planning
The listed pipe weight is a reference value for estimating, handling, support coordination, and structural load reviews. The water-filled value shown in the source can help with preliminary comparison of operating or test-related loading, but project calculations should use the applicable design basis and confirmed product information.
Schedule selection and verification
Schedule 160 identifies a heavy-wall dimension series; it is not, by itself, a complete design qualification or a universal pressure rating. Final selection should be checked against the project specification, material requirements, joining method, temperature and service conditions, applicable piping code, and supplier documentation.
For a CAD workflow, use the downloadable DWG alongside the dimension table rather than relying on a scaled drawing alone. Before fabrication, confirm units, tolerances, end preparation, material grade, and any fitting or flange requirements separately.
Additional Questions About 1 Inch Schedule 160 Pipe
Is NPS 1 the same nominal size as DN25?
Yes. In this reference, NPS 1 corresponds to DN25. The nominal designation is used for identification, while the listed OD, wall thickness, and ID control dimensional checks.
Does the schedule determine the pipe material grade?
No. The schedule describes the pipe dimension series. Material grade, manufacturing requirements, end details, and other procurement requirements must be specified and verified separately.
Can the listed weight be used for a final support design?
It can support preliminary estimating and coordination, but final support and structural checks should account for the project design basis, attachments, contents, insulation, loads, and confirmed product data.
Why should the DWG be checked against the table?
A CAD file supports layout and drafting work, while the table provides the stated reference dimensions. Reviewing both helps identify unit, scaling, or configuration issues before the drawing is released for fabrication.