What’s the difference between the stainless steel Schedule 40 pipe and Schedule 10 pipe？
When selecting stainless steel pipes for industrial, commercial, or structural applications, two of the most common wall thickness classifications you’ll encounter are Schedule 40 (SCH40) and Schedule 10 (SCH10). These “schedules” refer to standardized pipe wall thicknesses that directly impact a pipe’s weight, strength, pressure rating, internal diameter, cost, and suitability for various applications.
In this article, we’ll break down the key differences between SCH40 and SCH10 stainless steel pipes to help you make the right choice for your specific project.
Ganyeah Group Stainless Steel Schedule 40 pipes
1.Wall Thickness
Schedule 40 (SCH40): Thicker walls; considered the “standard” wall thickness for many pressure-based applications.
Schedule 10 (SCH10): Thinner walls; classified as lightweight or thin-wall pipes, ideal for low-pressure or weight-sensitive systems.
Key Point: For the same Nominal Pipe Size (NPS), SCH40 pipes always have thicker walls than SCH10 pipes. For example:
| NPS Size | SCH10 Wall Thickness | SCH40 Wall Thickness | Thickness Ratio |
| 1/2″ | 1.24 mm (0.049″) | 2.77 mm (0.109″) | 2.2× |
| 2″ | 2.11 mm (0.083″) | 3.91 mm (0.154″) | 1.85× |
| 8″ | 5.59 mm (0.220″) | 8.18 mm (0.322″) | 1.46× |
2.Weight
SCH40: Heavier due to thicker walls and higher material usage.
SCH10: Lighter, making it ideal for applications where weight reduction is important (e.g., 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: Smaller internal diameter due to thicker wall, which can reduce flow capacity.
SCH10: Larger internal diameter, allowing better flow rates and lower fluid resistance for the same pipe size.
5.Cost
SCH40: More expensive due to higher material content and production cost.
SCH10: More economical, especially suitable for large-scale installations where cost is a concern.
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
| Feature | Schedule 40 Pipe | Schedule 10 Pipe |
| Wall Thickness | Thick (Standard duty) | Thin (Lightweight duty) |
| Weight | Heavy | Light |
| Inside Diameter | Smaller | Larger |
| Pressure Capacity | High | Low |
| Cost | Higher | Lower |
| Rigidity/Strength | High (More impact resistant) | Low (More flexible, less durable) |
| Welding Difficulty | Easier to weld | Requires higher welding skill |
| Typical Applications | High-pressure fluid, structure | Ventilation, low-pressure lines |
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 10S and Schedule 40S 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.