This reference page brings together the key dimensional and weight data for 12 inch Schedule 10 pipe, also identified as NPS 12 and DN300. Use it when checking piping layouts, preparing material takeoffs, reviewing fabrication information, or coordinating drawing details.
The table is intended for quick technical lookup. For related work, connect this page to the site’s pipe dimensions and schedules reference, pipe weight resources, pipe fittings and flanges pages, and CAD/DWG downloads. Those links help readers move from a straight-pipe dimension check to the connected components and drafting information needed for a complete piping review.
Schedule 10 pipe 12 inch (DN300) is a standard steel pipe size commonly used in piping design, fabrication, drafting, and estimation work. This page provides the standard dimensions, wall thickness, inside diameter, and weight per meter for NPS 12 Schedule 10 pipe based on ASME B36.10.
12 Inch Schedule 10 Pipe Dimensions
- Nominal Pipe Size (NPS): 12 inch
- Diameter Nominal (DN): DN300
- Outside Diameter (OD): 323.9 mm
- Wall Thickness: 4.57 mm
- Inside Diameter (ID): 314.76 mm
- Pipe Weight: 35.98 kg/m
- Pipe Weight Filled With Water: 113.7 kg/m
- Reference Standard: ASME B36.10
Schedule 10 Pipe 12 Inch Data Table
| Pipe Size | DN | OD (mm) | Wall Thickness (mm) | ID (mm) | Weight (kg/m) |
|---|---|---|---|---|---|
| 12 inch | 300 | 323.9 | 4.57 | 314.76 | 35.98 |
What Does Schedule 10 Mean?
Schedule 10 refers to the wall thickness series of the pipe. For the same nominal pipe size, the outside diameter remains fixed while the wall thickness changes depending on the schedule. A thicker wall generally increases pipe weight and reduces the inside diameter.
Typical Uses of 12 Inch Schedule 10 Pipe
NPS 12 Schedule 10 pipe is commonly used in water transfer lines, utility systems, low-pressure process piping, drainage applications, and general plant layout or fabrication work where a lighter wall thickness is suitable. It is also a useful reference size for piping design and material estimation.
Why Pipe Weight Matters
Pipe weight per meter is important for transport planning, support design, structural loading, fabrication estimates, and lifting calculations. Even for medium-size piping systems, total installed weight can affect support spacing, handling methods, and project cost.
12 Inch Schedule 10 Pipe Calculation Notes
The listed weight is based on standard steel pipe dimension data using the outside diameter and wall thickness of the pipe. Actual product weight may vary slightly depending on manufacturing tolerance, material grade, and supplier standard.
Frequently Asked Questions
What is the outside diameter of 12 inch Schedule 10 pipe?
The outside diameter is 323.9 mm.
What is the wall thickness of DN300 Schedule 10 pipe?
The wall thickness is 4.57 mm.
What is the inside diameter of NPS 12 Schedule 10 pipe?
The inside diameter is 314.76 mm.
How much does 12 inch Schedule 10 pipe weigh?
The approximate weight is 35.98 kg/m.
Which standard covers this pipe size?
This dimension data is based on ASME B36.10 for welded and seamless wrought steel pipe.
Conclusion
Schedule 10 pipe 12 inch (DN300) has an outside diameter of 323.9 mm, wall thickness of 4.57 mm, inside diameter of 314.76 mm, and a weight of 35.98 kg/m. It is a useful reference for piping design, drafting, estimating, and fabrication work.
How to Use This Pipe Reference
Start with the nominal designation when identifying the pipe in a specification, model, or material list. The outside diameter is useful for layout coordination, clearances, clamps, supports, and connection planning. Wall thickness and inside diameter are more relevant when reviewing fabrication details, flow passage, and the relationship between the nominal designation and the physical section.
The listed weight per meter supports preliminary quantity takeoffs and handling reviews. For a complete estimate, multiply the reference weight by the applicable pipe length and then account for fittings, flanges, valves, coatings, insulation, supports, and any contents. The filled-with-water value shown in the source is a separate reference for considering added operating or test-related loading.
Schedule, Size, and Design Verification
Schedule identifies a wall-thickness series; it is not, by itself, a complete pressure-design qualification. A piping engineer must confirm material specification, temperature, pressure, corrosion allowance, joining method, applicable design code, and manufacturer requirements before selecting the pipe for service. The dimensions on this page are therefore best used as reference data rather than as a substitute for project-specific engineering verification.
Drafting and CAD Workflow
The downloadable DWG can support layout and drafting tasks involving this pipe size. Before incorporating it into a project drawing, check the drawing units, insertion scale, layer structure, centerline conventions, and connection details against the project’s CAD standards. Coordinate the straight-pipe geometry with the applicable fitting, flange, support, and valve references so that the model reflects the complete piping arrangement.
Additional Questions About 12 Inch Schedule 10 Pipe
Does Schedule 10 alone define the pipe’s pressure rating?
No. Schedule describes the wall-thickness series, but pressure capability also depends on material, temperature, design code, manufacturing requirements, corrosion allowance, and the service conditions.
Why are NPS and DN both shown?
NPS is the nominal pipe-size designation commonly used in U.S. piping references, while DN is the metric nominal designation used in many international documents. Showing both helps reduce identification errors when drawings, specifications, and supplier documents use different terminology.
Can the listed weight be used as the final procurement weight?
It is a reference value for estimating and preliminary planning. Actual supplied weight can vary with manufacturing tolerances, material requirements, product condition, and supplier documentation, so procurement records should be checked before finalizing shipping or structural loads.
What should be checked before using the DWG in a project?
Confirm units, scale, geometry, layer conventions, connection assumptions, and compatibility with the project’s drafting standards. Also verify the model against the governing project specification and the required fittings or connection components.