What does Schedule 10 mean?
Schedule 10 is a wall thickness grade (Pipe Schedule) in the steel pipe sizing system, typically written as Sch 10 / Schedule 10.
In the ASME B36.10M (carbon and alloy steel pipes) and ASME B36.19M (stainless steel pipes) systems, “Schedule” is used to denote the wall thickness grade of a pipe.
For example:
- NPS 4 Sch 10
- NPS 6 Sch 10
- NPS 8 Sch 10
Schedule 10 ≠ 10 mm wall thickness
The schedule number is a standardized designation for wall thickness grades; the actual wall thickness can only be determined in conjunction with the NPS (Nominal Pipe Size).
How Does Schedule 10 Relate to NPS?
NPS determines the nominal size of a pipe, while Schedule determines the corresponding wall thickness specification.
Pipe Schedule is a standardized system of pipe sizes; for different NPS sizes, Schedule 10 corresponds to different actual wall thicknesses.
Schedule 10 Pipe Dimensions
The dimensions of Schedule 10 pipe depend on the Nominal Pipe Size (NPS) and the applicable dimensional standard. For carbon and alloy steel pipe, dimensions are generally specified according to ASME B36.10M, while stainless steel pipe uses ASME B36.19M, where the corresponding designation is Schedule 10S. The “S” suffix distinguishes stainless steel pipe from the Schedule designations used in B36.10M.
The outside diameter (OD) is determined by the NPS and generally remains the same across different schedules for a given NPS. The wall thickness (WT) changes with the schedule, which in turn determines the approximate inside diameter (ID).
Approximate ID can be calculated as:
ID = OD − 2 × Wall Thickness
Schedule 10 Carbon Steel Pipe Dimensions — ASME B36.10M
| NPS | DN | OD | Schedule 10 Wall Thickness | Approx. ID |
| 1/2″ | DN15 | 21.3 mm | 2.11 mm | 17.08 mm |
| 3/4″ | DN20 | 26.7 mm | 2.11 mm | 22.48 mm |
| 1″ | DN25 | 33.4 mm | 2.77 mm | 27.86 mm |
| 1-1/4″ | DN32 | 42.2 mm | 2.77 mm | 36.66 mm |
| 1-1/2″ | DN40 | 48.3 mm | 2.77 mm | 42.76 mm |
| 2″ | DN50 | 60.3 mm | 2.77 mm | 54.76 mm |
| 2-1/2″ | DN65 | 73.0 mm | 3.05 mm | 66.90 mm |
| 3″ | DN80 | 88.9 mm | 3.05 mm | 82.80 mm |
| 4″ | DN100 | 114.3 mm | 3.05 mm | 108.20 mm |
| 6″ | DN150 | 168.3 mm | 3.40 mm | 161.50 mm |
| 8″ | DN200 | 219.1 mm | 3.76 mm | 211.58 mm |
| 10″ | DN250 | 273.1 mm | 4.19 mm | 264.72 mm |
| 12″ | DN300 | 323.9 mm | 4.57 mm | 314.76 mm |
The ID here is an approximate value calculated based on the OD and nominal wall thickness; it is not an independent standard size. The actual inner diameter is also influenced by factors such as manufacturing tolerances.
Schedule 10S Stainless Steel Pipe Dimensions — ASME B36.19M
Common sizes are as follows:
| NPS | DN | OD | Schedule 10S Wall Thickness | Approx. ID |
| 1/2″ | DN15 | 21.3 mm | 2.11 mm | 17.08 mm |
| 3/4″ | DN20 | 26.7 mm | 2.11 mm | 22.48 mm |
| 1″ | DN25 | 33.4 mm | 2.77 mm | 27.86 mm |
| 1-1/2″ | DN40 | 48.3 mm | 2.77 mm | 42.76 mm |
| 2″ | DN50 | 60.3 mm | 2.77 mm | 54.76 mm |
| 3″ | DN80 | 88.9 mm | 3.05 mm | 82.80 mm |
| 4″ | DN100 | 114.3 mm | 3.05 mm | 108.20 mm |
| 6″ | DN150 | 168.3 mm | 3.40 mm | 161.50 mm |
| 8″ | DN200 | 219.1 mm | 3.76 mm | 211.58 mm |
| 10″ | DN250 | 273.1 mm | 4.19 mm | 264.72 mm |
| 12″ | DN300 | 323.9 mm | 4.57 mm | 314.76 mm |
For these common sizes, the wall thickness values for 10S and B36.10M Schedule 10 are the same; however, this does not mean that the two standards are identical.
ASME B36.19M explicitly stipulates that the wall thicknesses of certain S-series sizes do not align with those of B36.10M; for example, Schedule 10S for NPS 14–22 differs from Schedule 10 in B36.10M.
Learn more about the key differences between ASME B36.10M and ASME B36.19M, including their applications, dimensions, and pipe schedule designations.
Schedule 10 vs Schedule 10S: What Is the Difference?
| Item | Schedule 10 | Schedule 10S |
| Main Standard | ASME B36.10M | ASME B36.19M |
| Typical Material | Carbon / Alloy Steel | Stainless Steel |
| Schedule Designation | Sch 10 | Sch 10S |
| OD System | NPS-based | NPS-based |
| Wall Thickness | Defined by B36.10M | Defined by B36.19M |
| Same for All Sizes? | — | No |
| Can They Be Used Interchangeably? | No | No |
Schedule 10 and Schedule 10S should not be treated as interchangeable designations. Schedule 10 generally refers to the B36.10M dimensional system, while Schedule 10S refers to the stainless steel pipe dimensions specified in B36.19M.
How Much Does Schedule 10 Pipe Weigh?
The weight of a Schedule 10 pipe depends mainly on its outside diameter (OD), wall thickness (WT), pipe length, and material density. For a given NPS, Schedule 10 defines the nominal wall thickness, which can then be used to calculate the theoretical pipe weight.
For standard steel pipe, ASME B36.10M provides nominal plain-end pipe weights for welded and seamless wrought steel pipe. The standard gives pipe weight in lb/ft and kg/m.
Schedule 10 Pipe Weight per Meter
For carbon steel pipe, the theoretical plain-end weight can be calculated from the outside diameter and wall thickness:
Weight (kg/m) ≈ 0.02466 × t × (OD − t)
Where:
- OD= outside diameter in mm
- t= nominal wall thickness in mm
- Weight= theoretical pipe weight in kg/m
Schedule 10 Pipe Weight per Meter
Yes.
The same nominal OD and wall thickness can produce slightly different theoretical weights when different materials are used because material density varies.
For example:
- Carbon steel
- Stainless steel
- Alloy steel
do not have exactly the same density.
Therefore, a Schedule 10 pipe specification should not be used by itself to determine the final shipping weight.
FAQ
What Applications Is Schedule 10 Pipe Suitable For?
Schedule 10 pipe is commonly used for water supply, HVAC systems, fire protection, compressed air, industrial utility piping, and certain structural or mechanical applications. Its suitability depends on the pipe size, material, design pressure, operating temperature, and applicable standards. For higher-pressure or demanding services, the required wall thickness should be verified through engineering calculations.
What is the difference between Schedule 10 and Schedule 40?
The main difference is wall thickness. For the same NPS, Schedule 40 generally has a thicker wall than Schedule 10. This normally results in a higher pipe weight and smaller internal diameter. The appropriate schedule depends on the project’s design and applicable code requirements.
What is the wall thickness of Schedule 10 pipe?
Schedule 10 wall thickness varies with pipe size. For example, common sizes include approximately 2.77 mm for 2-inch pipe, 3.05 mm for 4-inch pipe, 3.40 mm for 6-inch pipe, and 4.57 mm for 12-inch pipe. Always check the applicable dimensional standard for the specified NPS.
