This reference page is for engineers, designers, fabricators, and estimators checking Schedule 160 pipe 1 1/4 inch dimensions. Use the data below when preparing piping layouts, material takeoffs, fabrication drawings, support-load checks, or CAD references.
For related terminology, see the guide to pipe schedules, the NPS and DN size relationship, and the broader pipe dimensions reference. These resources help distinguish nominal size, outside diameter, wall thickness, and inside diameter when comparing pipe sizes.
Schedule 160 pipe 1 1/4 inch (DN32) 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 1/4 Schedule 160 pipe based on ASME B36.10.
1 1/4 Inch Schedule 160 Pipe Dimensions
- Nominal Pipe Size (NPS): 1 1/4 inch
- Diameter Nominal (DN): DN32
- Outside Diameter (OD): 42.2 mm
- Wall Thickness: 6.35 mm
- Inside Diameter (ID): 29.5 mm
- Pipe Weight: 5.61 kg/m
- Pipe Weight Filled With Water: 6.29 kg/m
- Reference Standard: ASME B36.10
- Pipe Type: Steel Pipe
Schedule 160 Pipe 1 1/4 Inch Data Table
| Pipe Size | DN | OD (mm) | Wall Thickness (mm) | ID (mm) | Weight (kg/m) |
|---|---|---|---|---|---|
| 1 1/4 inch | 32 | 42.2 | 6.35 | 29.5 | 5.61 |
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 1/4 Inch Schedule 160 Pipe
NPS 1 1/4 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 1/4 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 1/4 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 1/4 inch Schedule 160 pipe?
The outside diameter is 42.2 mm.
What is the wall thickness of DN32 Schedule 160 pipe?
The wall thickness is 6.35 mm.
What is the inside diameter of NPS 1 1/4 Schedule 160 pipe?
The inside diameter is 29.5 mm.
How much does 1 1/4 inch Schedule 160 pipe weigh?
The approximate weight is 5.61 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 1/4 inch (DN32) has an outside diameter of 42.2 mm, wall thickness of 6.35 mm, inside diameter of 29.5 mm, and a weight of 5.61 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
The listed dimensions describe the pipe geometry used for design and drafting reference. The nominal designation identifies the size convention, while the outside diameter and wall thickness define the physical section. The inside diameter is important when checking flow space, bore clearance, internal coatings, and compatibility with connected components.
Schedule is a wall-thickness designation
Schedule 160 identifies a heavy-wall series; it is not, by itself, a complete pressure rating. Pressure capability also depends on material specification, temperature, manufacturing requirements, joining method, corrosion allowance, and the governing design code. Confirm those requirements before using the pipe in a pressure design.
Why the outside diameter and inside diameter both matter
Pipe connections, clamps, supports, and many fitting interfaces are coordinated around the outside diameter and nominal size. Internal flow calculations and bore checks use the inside diameter. A heavier schedule retains the nominal size designation while using more of the cross-section for wall thickness, leaving less internal passage and increasing the pipe’s mass.
Using the weight data in project work
The dry weight supports material estimates, transport planning, lifting studies, support reactions, and structural checks. The filled-with-water value is a useful reference for considering the additional load associated with a water-filled line. For final design, account for the actual fluid, insulation, valves, fittings, supports, corrosion protection, and project-specific tolerances.
Drawing and procurement checks
- Show the nominal size and schedule clearly in the piping specification or drawing note.
- Check that connected fittings, flanges, valves, and threaded or welded components use compatible dimensions and end details.
- Use the downloadable DWG reference as a drafting aid, then verify project units, layer conventions, and connection details before issuing a drawing.
- Keep dimensional standards separate from material, testing, and certification requirements in the procurement specification.
For related component checks, continue to the references for pipe fittings, pipe flanges, and pipe weight calculations.
Additional Questions About Schedule 160 Pipe
Does Schedule 160 alone establish the pipe pressure rating?
No. The schedule describes a dimensional wall-thickness series. A pressure design also requires the applicable material, temperature, code, corrosion allowance, manufacturing, and joining requirements.
Why is DN32 associated with NPS 1 1/4 pipe?
DN and NPS are different nominal sizing systems used to identify corresponding pipe sizes. The designation does not mean that the nominal label is the same as the measured inside or outside diameter.
Can the pipe weight be used as the complete support load?
No. The listed pipe weight is only one part of an installed-load assessment. Add the relevant contents, fittings, valves, insulation, coatings, supports, and other project-specific items.
Should the DWG file be used without checking the project specification?
No. Use the file as a reference starting point. Confirm units, tolerances, end preparation, connection details, material requirements, and the project drafting standard before using it for fabrication or construction.