When it comes to high-temperature and corrosion-resistant stainless steel materials, Stainless Steel 310 and Stainless Steel 310S Bars are two of the most commonly used grades. Both these materials belong to the austenitic stainless steel family and are well-known for their outstanding resistance to heat, oxidation, and corrosion. However, while they may seem similar, there are important differences between the two that can affect performance, durability, and suitability for certain applications.
This blog will help you understand the major differences between Stainless Steel 310 Bars and Stainless Steel 310S Bars, their properties, advantages, and which one you should choose depending on your industrial needs.
1. Overview of Stainless Steel 310 and 310S Bars
Stainless Steel 310 Bars and Stainless Steel 310S Bars are both chromium-nickel alloys that provide excellent strength and oxidation resistance at high temperatures. They are designed for use in environments where heat and corrosion are common problems, such as furnaces, heat exchangers, chemical plants, and power stations.
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Stainless Steel 310 Bars are known for their high carbon content, which increases their strength and hardness.
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Stainless Steel 310S Bars are the low-carbon version of grade 310, designed for better weldability and reduced carbide precipitation.
The addition of chromium (around 25%) and nickel (around 20%) makes both grades highly resistant to oxidation and scaling even in continuous service up to 1100°C.
2. Chemical Composition
The main difference between these two grades lies in their carbon content.
| Element | Stainless Steel 310 | Stainless Steel 310S |
|---|---|---|
| Carbon (C) | 0.25% max | 0.08% max |
| Chromium (Cr) | 24–26% | 24–26% |
| Nickel (Ni) | 19–22% | 19–22% |
| Manganese (Mn) | 2% max | 2% max |
| Silicon (Si) | 1.5% max | 1.5% max |
| Phosphorus (P) | 0.045% max | 0.045% max |
| Sulfur (S) | 0.03% max | 0.03% max |
| Iron (Fe) | Balance | Balance |
The lower carbon content in Stainless Steel 310S Bars helps reduce the risk of carbide precipitation during welding or prolonged exposure to high temperatures. This makes Stainless Steel 310S Bar more suitable for applications that require frequent welding or where corrosion resistance at weld joints is important.
3. Mechanical Properties
Both grades have strong mechanical properties, but Stainless Steel 310 Bars generally have higher strength due to their increased carbon levels.
| Property | Stainless Steel 310 | Stainless Steel 310S |
|---|---|---|
| Tensile Strength | 515 MPa (min) | 515 MPa (min) |
| Yield Strength | 205 MPa (min) | 205 MPa (min) |
| Elongation | 40% (min) | 40% (min) |
| Hardness (Brinell) | 217 (max) | 217 (max) |
Even though the mechanical properties are quite similar, the lower carbon content in 310S stainless steel round bar gives it an advantage during forming, bending, and welding processes.
4. Heat Resistance and Oxidation
Both Stainless Steel 310 Bars and Stainless Steel 310S Bars have excellent oxidation resistance due to their high chromium and nickel content.
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Stainless Steel 310 Bars can be used for continuous service up to 1100°C and intermittent service up to 1150°C.
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Stainless Steel 310S Bars also perform well in similar temperature ranges but have better resistance to thermal fatigue and stress cracking because of their lower carbon content.
This means 310S stainless steel round bar is preferred in applications involving temperature cycling, where materials frequently heat up and cool down.
5. Corrosion Resistance
In general, both grades perform well in oxidizing and mildly reducing environments. However, Stainless Steel 310S Bars provide better resistance in applications involving frequent exposure to moisture or temperature changes.
The reduced carbon content minimizes the formation of chromium carbides along the grain boundaries, which is a common cause of intergranular corrosion. This makes Stainless Steel 310S Bars more reliable for welded parts and for use in areas prone to corrosion after high-temperature exposure.
6. Fabrication and Weldability
When it comes to welding, Stainless Steel 310S Bars Manufacturer products are more popular because 310S is easier to weld and fabricate compared to 310.
The lower carbon content reduces the risk of carbide precipitation, making Stainless Steel 310S Bar ideal for applications that require extensive welding or bending. Both grades can be welded using standard methods like TIG, MIG, or arc welding, but 310S stainless steel round bar offers smoother performance during post-weld heat treatment.
7. Applications of Stainless Steel 310 and 310S Bars
The wide range of applications for both materials shows their versatility and reliability in industrial use.
Applications of Stainless Steel 310 Bars
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Furnace parts and components
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Power generation and boiler equipment
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Heat exchangers and radiant tubes
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Jet engine parts
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Cement and petrochemical industries
Applications of Stainless Steel 310S Bars
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Chemical and petrochemical processing plants
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Heat treatment equipment
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Food processing and cryogenic applications
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Refineries and pharmaceutical industries
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Equipment that undergoes frequent welding or forming
The 310S stainless steel round bar is particularly valued in industries that require both high temperature and corrosion resistance, along with good weldability.
8. Differences in Cost and Availability
The difference in cost between the two grades is usually minor. Stainless Steel 310S Bars can sometimes be slightly more expensive due to the additional processing required to control carbon content during manufacturing.
However, the cost difference is often justified by the benefits Stainless Steel 310S Bars offer—such as better weldability, longer service life, and lower maintenance costs in the long term.
Most Stainless Steel 310S Bars Manufacturer companies supply both grades in various sizes, shapes, and finishes to meet diverse industrial demands.
9. Advantages of Stainless Steel 310S Bars
Choosing Stainless Steel 310S Bars provides several advantages:
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Excellent resistance to oxidation and scaling.
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Improved weldability and formability.
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Stable mechanical strength at high temperatures.
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Lower risk of intergranular corrosion after welding.
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Long service life and minimal maintenance.
The 310S stainless steel round bar is also suitable for both cryogenic and high-temperature conditions, making it one of the most versatile options for engineering applications.
10. Which One Should You Choose?
The choice between Stainless Steel 310 Bars and Stainless Steel 310S Bars depends on your specific application requirements.
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Choose Stainless Steel 310 Bars if your project involves very high temperatures and you need maximum strength and hardness.
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Choose Stainless Steel 310S Bars if your application involves frequent welding, exposure to fluctuating temperatures, or requires better resistance to thermal fatigue and corrosion.
If you’re working in industries like chemical processing, heat treatment, or refineries, Stainless Steel 310S Bar is usually the more practical and durable choice.
Conclusion
Both Stainless Steel 310 Bars and Stainless Steel 310S Bars are high-performance materials designed to handle extreme environments. The key difference lies in the carbon content—310S being the low-carbon version offers superior weldability and corrosion resistance, while 310 provides greater strength at elevated temperatures.
When selecting between these two, it’s important to consider factors like temperature range, exposure conditions, and fabrication needs. A trusted Stainless Steel 310S Bars Manufacturer can help ensure you get the right material that meets your specific performance requirements.
