What’s the difference between the stainless steel Schedule 40 pipe and Schedule 10 pipe？

When choosing stainless steel pipes for fluid transport, structural support, or mechanical systems, understanding the difference between Schedule 40 and Schedule 10 stainless steel pipes is essential. These “schedules” define the wall thickness of pipes, affecting their pressure handling, flow capacity, cost, and durability.  In this article, Ganyeah Group explains how to select the right pipe for your application by comparing Schedule 40 vs Schedule 10.

The term “Schedule” (abbreviated as SCH) refers to the standardized wall thickness of pipes, as defined by ASME B36.10M and B36.19M. For stainless steel, the schedules typically used are Schedule 5S, 10S, 40S, and 80S. In most industrial applications, Schedule 10S and Schedule 40S are the most commonly specified. Here are the difference between Schedule 40 and Schedule 10 stainless steel pipes:

Ganyeah Group Stainless Steel Schedule 40 pipes

1.Wall Thickness

Schedule 40 Pipe: Has thicker walls and is suitable for higher pressure or mechanical stress. For example, a 2-inch SCH40 pipe has a wall thickness of ~3.91 mm.

Schedule 10 Pipe: Thinner walls make these pipes lighter and more economical. The same 2-inch SCH10 pipe has a ~2.11 mm wall thickness.

Key Point: For the same Nominal Pipe Size (NPS), SCH40 pipes always have thicker walls than SCH10 pipes. For example:

2.Weight

SCH40 pipes are heavier due to more material, which may require stronger supports or lifting equipment.

SCH10 pipes are easier to transport and install, especially in HVAC systems, overhead piping, aerospace structures

3.Pressure Rating

SCH40: With greater wall thickness, SCH40 pipes can withstand significantly higher internal pressures. It’s the preferred choice for medium to high-pressure fluid transport.

SCH10: Designed for low-pressure systems such as ventilation, drainage, or low-pressure liquid flows. Not suitable for high-pressure environments.

4.Inside Diameter (ID)

Since the outer diameter (OD) is fixed by NPS, the thicker the wall, the smaller the inside diameter.

SCH40 Pipe: Smaller internal diameter due to thicker wall, which can reduce flow capacity.

SCH10 Pipe: Larger internal diameter, allowing better flow rates and lower fluid resistance for the same pipe size.

5.Cost

Schedule 10 stainless steel pipes are more cost-effective, particularly for large-scale or non-pressurized systems. Schedule 40 pipes, while more expensive, offer long-term performance and durability for critical systems.

Ganyeah Group Stainless Steel Schedule 10 pipes

6.Rigidity & Mechanical Strength

SCH40: Greater rigidity and strength. It resists external loads, bending, and impact damage more effectively—ideal for structural or exposed applications.

SCH10: More flexible and easier to bend, but also more prone to deformation or denting under mechanical stress. Requires careful handling during installation.

7.Welding & Fabrication

SCH40: Moderate wall thickness allows easier welding, especially with common methods like TIG or MIG welding.

SCH10: Due to thin walls, welding is more delicate and prone to burn-through. Skilled welders and precise heat control are necessary to ensure quality joints.

8.Typical Applications

Stainless Steel Schedule 40 Pipe:

• Pressurized water supply systems (hot & cold)
• Fire protection (sprinkler systems)
• Compressed air lines (medium to high pressure)
• Corrosive fluid transportation in chemical industries
• Structural supports, handrails, and frames
• Food and beverage processing lines

Stainless Steel Schedule 10 Pipe:

• HVAC ductwork and low-pressure air systems
• Exhaust and vent piping
• Low-pressure condensate return lines
• Instrument air supply (low pressure)
• Applications requiring larger internal diameter with minimal pressure
• Lightweight structural uses or aesthetic tubing

Quick Comparison Table

How to Choose Between SCH40 and SCH10?

Choose Schedule 40 pipe if:

You need a pipe that can handle medium to high internal pressure

The application involves structural loads, external impacts, or frequent mechanical stress

You want long-term durability and resistance to deformation

Choose Schedule 10 pipe if:

You’re dealing with non-pressurized or low-pressure systems like air, venting, or exhaust

Weight savings and cost reduction are critical

You require a larger internal diameter without increasing nominal pipe size

Your application can tolerate lower mechanical strength

Important Notes

The “S” in SCH10S or SCH40S refers to a wall thickness standard tailored for stainless steel and other alloy pipes. Though often omitted in casual usage, SCH10 and SCH40 for stainless steel are technically SCH10S and SCH40S under standards like ASTM A312.

Always consult standard reference tables or engineering guidelines (e.g., ASME B36.19M) when choosing pipe wall thickness for critical systems.

Pressure ratings must be calculated based on working temperature, media, and installation method—don’t rely solely on schedule numbers.

Need Stainless Steel Pipes? Choose Ganyeah Group

Ganyeah Group is a professional manufacturer and global supplier of stainless steel pipes, offering full ranges of Schedule 10 and Schedule 40 stainless steel pipes in materials such as 304, 316L, 321, and Duplex stainless steel. Whether you need pipes for HVAC, water systems, chemical processing, or structural applications, we deliver precision-engineered, quality-assured solutions worldwide.

Contact us today for pricing, stock availability, and technical support.