What is Schedule 40 Pipe? Dimensions & Sizes

Schedule 40 pipe (or SCH 40 for short) is one of the most widely used steel pipes in the industry, offering the perfect balance of strength, affordability, and versatility. It follows a standardized wall thickness, making it a reliable choice for everything from plumbing and structural support to industrial applications. 

Keep reading as we break down what Schedule 40 pipe is, how thick it is, and how it compares to other schedules, so you can make the right choice for your project.

What Does Schedule 40 Mean?

• The term “Schedule 40“, sometimes shortened to SCH 40, refers to a standardized system that defines a pipe’s wall thickness. 
• The “40” is simply a designation used within the American National Standards Institute (ANSI) schedule system. 

While the outer diameter remains consistent for each nominal pipe size (NPS), the wall thickness increases as the schedule number rises. Schedule 40 pipe hits the sweet spot—thick enough to handle significant pressure, but not so thick that it becomes difficult or expensive to work with.

What is the ANSI Pipe Schedule?

The ANSI (short for American National Standards Institute) pipe schedule system ensures consistency in pipe wall thickness across different manufacturers, making it easier for engineers and contractors to select the right pipe for the job. This system includes various schedules, like 10, 40, 80, and so on, each with a thicker wall as the number increases.

• For detailed Schedule 40 pipe size information, check out our steel pipe sizing chart here or dive into our steel pipe basics guide to learn more.

How Thick is Schedule 40 Pipe?

The wall thickness of Schedule 40 pipe depends on its nominal size. Here are a few examples:

• 1-inch Schedule 40 pipe: 0.133-inch wall thickness
• 2-inch Schedule 40 pipe: 0.154-inch wall thickness
• 6-inch Schedule 40 pipe: 0.28-inch wall thickness

This level of thickness makes Schedule 40 ideal for a range of applications, including water and gas transport, mechanical systems, and structural projects. It’s thick enough to provide durability and pressure resistance while still being easy to install and work with.

What’s the Difference Between Schedule 40 vs. 80 Steel Pipe Thickness?

The biggest difference between Schedule 40 and Schedule 80 steel pipe is wall thickness. SCH 80 has a thicker wall, making it stronger and better suited for high-pressure applications. For example, a 2-inch Schedule 80 pipe has a 0.218-inch wall thickness, compared to 0.154 inches for SCH 40. You can visualize their differences better with the help of the below image:

Source: DripDepot

If your project requires extra strength and durability, such as in chemical processing or industrial piping, Schedule 80 might be the better choice. But for general-purpose use, Schedule 40 gets the job done efficiently.

Get High-Quality Schedule 40 Steel Pipes for Your Projects Today!

When it comes to steel, Service Steel Warehouse delivers premium quality and exceptional service. Every steel product we supply meets strict ASTM standards, ensuring superior performance in any application. Looking for top-grade carbon Schedule 40 steel pipe? We have an extensive inventory ready to ship fast. Request a free quote or give us a call today!