Pipe Schedule 10 vs 40 vs 80: Which One Should You Choose?

When selecting and purchasing steel pipes, relying solely on the diameter is not sufficient; you must also specify the pipe schedule.

If you're unsure or still considering which wall thickness grade is most suitable, this article will help you.

What Is Pipe Schedule?

Pipe schedule refers to wall thickness and is a system used to standardize pipe wall thickness.

There are two key specifications for pipes: the nominal diameter (DN or NPS), which determines the pipe's outer diameter, and the schedule (SCH), which determines the pipe’s wall thickness.

Given a fixed outer diameter, the wall thickness increases with the Schedule rating. The higher the SCH value, the thicker the wall, the higher the pressure rating, and the smaller the inner diameter.

In actual procurement and design, engineers and procurement personnel typically refer to pipe schedule charts or standard pipe schedule charts to understand these differences.

The table below lists common pipe diameter and wall thickness data based on the ASME B36.10 standard.

cs pipe schedule chart

SCH 10 vs SCH 40 vs SCH 80 – Key Differences

SCH 10, SCH 40, and SCH 80 are the three most commonly used wall thickness grades in the Pipe Schedule system.

The main differences can be summarized as follows: the higher the number, the thicker the wall, the heavier the pipe, the higher the pressure rating, and the higher the cost.

SCH 10 — Thin-walled Pipe

Typically used for stainless steel (304/316L) and is often denoted as SCH 10S.

DN100/4, stainless steel SCH 10S with a wall thickness of 2.77 mm.

Pipes of this grade feature thin walls, light weight, and low cost, and are commonly used in water supply and drainage systems, low-pressure conveyance, and HVAC applications.

SCH 40 — Standard Wall Thickness

This is the most common standard grade in industrial piping and offers the best value for money. Unless there are specific requirements, SCH 40 is often the default choice for industrial piping.

DN100/4, carbon steel SCH 40, wall thickness 6.02 mm.

SCH 40 is suitable for building structures, general industrial piping, and oil and gas applications (general-purpose).

SCH 80 — Thicker Wall Thickness

The wall thickness is significantly increased, resulting in higher pressure-bearing capacity; however, the corresponding pipe inner diameter is reduced, and both weight and cost increase.

DN100 / 4, Carbon Steel SCH 80, Wall Thickness 8.56 mm

In small-diameter pipes with threaded connections (DN ≤ 80 / 3), SCH 80 is a key application. Thread cutting reduces wall thickness, so SCH 80 must be used to ensure strength.

SCH 80 is commonly used in harsh environments such as chemical processing, high-pressure piping, and boiler systems.

How to Choose the Right Pipe Schedule?

When selecting the appropriate pipe schedule, it is essential to comprehensively consider both the performance characteristics of the steel pipe and the specific application scenario to choose the most suitable, economical, and safe wall thickness grade.

The most critical factor is the operating pressure requirement. For low-pressure systems (≤ 1.6 MPa), such as water supply, drainage, and ventilation, Sch 40 or Sch 10S can be selected. For medium-pressure systems (1.6–4.0 MPa), such as general industrial and building piping, Sch 40 or Sch 40S can be selected.

For high-pressure applications (≥ 4.0 MPa), such as chemical processing, oil and gas transmission, and boilers, Sch 80 or higher may be selected

However, the actual selection should be based on design drawings or pressure calculation reports, as high-temperature conditions can affect the material’s pressure-bearing capacity and may require thicker walls.

The higher the SCH rating, the thicker the wall, which means more material is used and costs increase accordingly. Therefore, select the most appropriate steel pipe wall thickness grade while ensuring that safety and performance requirements are met.

Conclusion

Selecting the appropriate pipe schedule is critical for project construction, as it directly impacts project safety, efficiency, and cost.

This article begins with pipe schedules and focuses on the application scenarios and material properties of the commonly used SCH 10, SCH 40, and SCH 80, providing a pipe schedule chart for reference.

Whether you are working with low-pressure systems or dealing with demanding environments such as oil and gas pipelines, Cortec Steel offers a comprehensive range of pipe wall thickness specifications from SCH 10 to SCH 160 to meet your diverse needs.

Contact us today to develop a customized pipe wall thickness solution tailored to your requirements.

FAQ

What is Pipe Schedule?

Pipe Schedule (SCH) refers to the wall thickness grade of a pipe. The higher the Schedule number, the thicker the pipe wall and the greater its pressure-bearing capacity.

What is the most common pipe schedule?

SCH 10, SCH 40, and SCH 80 cover most piping requirements.

What is the difference between SCH and standard wall thickness (STD, XS, XXS)?

STD (Standard) ≈ SCH 40

XS (Extra Strong) ≈ SCH 80

XXS (Double Extra Strong) ≈ SCH 160

In the American ASME B36.10/19 standard, “Schedule” is a more precise method of classifying wall thickness.