SCH 40 Carbon Steel Pipe: Standard weight for general use.
SCH 40 Steel Pipe is the most widely used standard wall-thickness pipe, typically manufactured to ASTM A53 or ANSI standard specifications. It provides a balanced ratio of strength, pressure handling, and weight, making it ideal for industrial, structural, and fluid-transport applications.
At JS FITTINGS, we help global clients navigate the complexities of piping specifications every day. This guide breaks down everything you need to know about SCH 40 carbon steel pipe, its technical capabilities, and how to select the right specification for your project.
Understanding the “Schedule” (SCH)
In the steel pipe industry, “Schedule” refers to the wall thickness of a pipe. Unlike Nominal Pipe Size (NPS), which tells you the outer diameter, the Schedule rating dictates the internal wall thickness. Schedule 40 (SCH 40) is designated as “Standard” weight for most pipe sizes.
SCH 40 covers almost all pipe sizes from NPS 1/8 to NPS 24. In common steel pipe wall thickness classes (such as Sch 5S, 10, 20, 40, 80, 160, XXS), the wall thickness increases with the Sch number. Sch 40 is thicker than Sch 10/20, with higher pressure resistance, but thinner than Sch 80/160, with lower pressure resistance. It strikes a good balance between mechanical strength, weight, and cost.
Technical Specifications & Standards
Most SCH 40 carbon steel pipes are manufactured to meet rigorous international standards, ensuring consistency across supply chains:
ASTM A53: The most common specification for black and hot-dipped galvanized welded and seamless steel pipe.
ASTM A106: Used specifically for seamless carbon steel pipe for high-temperature service.
Manufacturing Types: Available in both Seamless (for high-pressure integrity) and ERW (Electric Resistance Welded) for structural or low-pressure fluid transport.
Surface Finishes: Commonly supplied as black (uncoated) or galvanized (zinc-coated for corrosion resistance).
SCH 40 Carbon Steel Pipe Chart: Dimensions, Weight & Pipe Wall Thickness
Based on ASTM A53 – Standard Specification for Steel Pipe, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless.
| ipe Size (in) | Diameter (in) | Nominal Thickness (in) | Transverse Areas (in2) | Length of Pipe (ft per sq. foot of surface) | Volume (ft3/ft) | Weight | Number of Threads per inch of Screw | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| External | Internal | External | Internal | Steel | External Surface (ft) | Internal Surface (ft) | (lb/ft) | (kg/m) | ||||
| 1/8 | 0.405 | 0.27 | 0.07 | 0.13 | 0.06 | 0.07 | 9.43 | 14.20 | 0.0004 | 0.24 | 0.36 | 27 |
| ¼ | 0.540 | 0.36 | 0.09 | 0.23 | 0.10 | 0.13 | 7.07 | 10.49 | 0.0007 | 0.42 | 0.63 | 18 |
| 3/8 | 0.675 | 0.49 | 0.09 | 0.36 | 0.19 | 0.17 | 5.66 | 7.75 | 0.0013 | 0.57 | 0.84 | 18 |
| ½ | 0.840 | 0.62 | 0.11 | 0.55 | 0.30 | 0.25 | 4.55 | 6.14 | 0.0021 | 0.85 | 1.26 | 14 |
| ¾ | 1.050 | 0.82 | 0.11 | 0.87 | 0.53 | 0.33 | 3.64 | 4.64 | 0.0037 | 1.13 | 1.68 | 14 |
| 1 | 1.315 | 1.05 | 0.13 | 1.36 | 0.86 | 0.49 | 2.90 | 3.64 | 0.0060 | 1.68 | 2.50 | 11 ½ |
| 1 ¼ | 1.660 | 1.38 | 0.14 | 2.16 | 1.50 | 0.67 | 2.30 | 2.77 | 0.0104 | 2.27 | 3.38 | 11 ½ |
| 1 ½ | 1.900 | 1.61 | 0.15 | 2.84 | 2.04 | 0.80 | 2.01 | 2.37 | 0.0141 | 2.72 | 4.04 | 11 ½ |
| 2 | 2.375 | 2.07 | 0.15 | 4.43 | 3.36 | 1.08 | 1.61 | 1.85 | 0.0233 | 3.65 | 5.43 | 11 ½ |
| 2 ½ | 2.875 | 2.47 | 0.20 | 6.49 | 4.79 | 1.70 | 1.33 | 1.55 | 0.0333 | 5.79 | 8.62 | 8 |
| 3 | 3.500 | 3.07 | 0.22 | 9.62 | 7.39 | 2.23 | 1.09 | 1.25 | 0.0513 | 7.58 | 11.27 | 8 |
| 3 ½ | 4.000 | 3.55 | 0.23 | 12.56 | 9.89 | 2.68 | 0.95 | 1.08 | 0.0687 | 9.11 | 13.56 | 8 |
| 4 | 4.500 | 4.03 | 0.24 | 15.90 | 12.73 | 3.17 | 0.85 | 0.95 | 0.0884 | 10.79 | 16.06 | 8 |
| 5 | 5.563 | 5.05 | 0.26 | 24.30 | 20.00 | 4.30 | 0.69 | 0.76 | 0.1389 | 14.61 | 21.74 | 8 |
| 6 | 6.625 | 6.07 | 0.28 | 34.47 | 28.89 | 5.58 | 0.58 | 0.63 | 0.2006 | 18.97 | 28.23 | 8 |
| 8 | 8.625 | 7.98 | 0.32 | 58.42 | 50.02 | 8.40 | 0.44 | 0.48 | 0.3552 | 28.55 | 42.49 | 8 |
| 10 | 10.750 | 10.02 | 0.37 | 90.76 | 78.85 | 11.90 | 0.36 | 0.38 | 0.5476 | 40.48 | 60.24 | 8 |
| 12 | 12.750 | 11.94 | 0.41 | 127.64 | 111.90 | 15.74 | 0.30 | 0.32 | 0.7763 | 53.60 | 79.77 | 8 |
| 14 | 14.000 | 13.13 | 0.44 | 153.94 | 135.30 | 18.64 | 0.27 | 0.28 | 0.9354 | 63.00 | 93.75 | 8 |
| 16 | 16.000 | 15.00 | 0.50 | 201.05 | 176.70 | 24.35 | 0.24 | 0.25 | 1.2230 | 78.00 | 116.08 | 8 |
| 18 | 18.000 | 16.88 | 0.56 | 254.85 | 224.00 | 30.85 | 0.21 | 0.23 | 1.5550 | 105.00 | 156.26 | 8 |
| 20 | 20.000 | 18.81 | 0.59 | 314.15 | 278.00 | 36.15 | 0.19 | 0.20 | 1.9260 | 123.00 | 183.05 | 8 |
| 24 | 24.000 | 22.63 | 0.69 | 452.40 | 402.10 | 50.30 | 0.16 | 0.17 | 2.7930 | 171.00 | 254.48 | 8 |
(Note: These are standard dimensions. For full technical data sheets or specific wall thickness requirements for larger sizes, please contact our engineering team.)
Why Choose SCH 40 steel pipes for Your Project?
The popularity of SCH 40 carbon steel pipe stems from its versatility:
- Pressure Handling: It is the go-to choice for low-to-medium pressure applications including water, gas, air, and steam lines.
- Structural Strength: Beyond fluid transport, SCH 40 is frequently used in structural applications, such as building frames, railings, and heavy-duty posts, due to its superior impact resistance compared to thinner-walled tubing.
- Fabrication Ease: Because of its standardized wall thickness, it is highly compatible with standard fittings, flanges, and valves, making installation and maintenance straightforward.
Common Applications
- HVAC & Plumbing: Trusted for fire sprinkler systems, chilled water lines, and HVAC infrastructure.
- Oil & Gas: Used in gathering lines and low-pressure facility piping.
- Manufacturing: Serving as the backbone for plant piping, chemical processing, and agricultural irrigation systems.
Partner with JS FITTINGS for Your Piping Needs
Finding a reliable supplier for SCH 40, SCH 80, and SCH 160 carbon steel pipes requires more than just a warehouse—it requires technical expertise.At JS FITTINGS(jssteelpipes.com), we don’t just sell pipes; we provide comprehensive piping solutions. Whether you require standard ASTM A53 stock or specialized seamless pipes for critical industrial projects, our team ensures that every shipment meets your exact tolerance and certification requirements.
- Extensive Stock: Large inventory of carbon steel pipes ready for global shipping.
- Quality Assured: Full mill test reports (MTRs) and strict adherence to international standards.
- Expert Support: Our technical team is available to help you compare schedules (SCH 40 vs. SCH 80 vs. SCH 160) to ensure you aren’t over-specifying or under-building your project.
FAQ:
Q1. SCH 40 vs. SCH 80: What are the differences?
The key difference is wall thickness. SCH 80 is typically 30% to 100% thicker than SCH 40 for the same pipe size, making it significantly stronger, heavier, and able to withstand higher pressures. For a full comparison table covering all sizes, weight, cost, and application guidelines, please see our dedicated guide:▶ [Schedule 40 vs. Schedule 80: A Selection Guide].
Q2. Is Sch 40 a seamless pipe or a welded pipe?
Both!
● Seamless pipe: ASTM A106 Sch 40
● Welded pipe: ASTM A53 Sch 40
Q3. What is the pressure rating of Schedule 40 pipe?
The pressure rating of Schedule 40 pipe varies, depending on size, material, and temperature. At room temperature, the pressure rating of carbon steel Schedule 40 pipe ranges from approximately 700 psi to 2,200 psi (4.8 to 15.2 MPa), with smaller diameter pipes offering higher pressure ratings.
Q4. What is the thickness of Schedule 40 pipe?
The thickness of Schedule 40 pipe depends on its nominal size (NPS). Below are the wall thicknesses for the most commonly requested sizes:
● 2 inch SCH 40 pipe: 3.91 mm
● 4 inch SCH 40 pipe: 6.02 mm
● 6 inch SCH 40 pipe: 7.11 mm
● 8 inch SCH 40 pipe: 8.18 mm
● 10 inch SCH 40 pipe: 9.27 mm
For the complete list, please refer to the dimension chart above. Remember, for the same NPS, the outside diameter (OD) remains constant; only the wall thickness and inner diameter (ID) change.
Ready to start your order or need a custom quote?
Don’t settle for delays or sub-standard materials. Click below to discuss your project requirements with our experts.
👉 [Get a Free Quote for SCH 40 Steel Pipes ]
Email: info@jssteelpipes.com
WhatsApp: +8618003119682
