SUS316 vs. SUS316L Stainless Steel: Carbon Content
Dec 01, 2025
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When choosing stainless steel for critical applications, understanding the differences between SUS316 and SUS316L is essential. Both grades are austenitic stainless steels, renowned for their excellent corrosion resistance, mechanical properties, and versatility. The main difference lies in their carbon content, which affects weldability, corrosion resistance, and high-temperature performance.
What is SUS316 Stainless Steel?
SUS316 stainless steel is a type of austenitic stainless steel. It is primarily produced by adding molybdenum to 304 stainless steel, thereby improving its corrosion resistance, especially its resistance to pitting corrosion in chlorinated media and high-temperature seawater. This makes it widely used in chemical equipment, marine engineering, and other fields. It also has good plasticity and weldability, and is non-magnetic at room temperature.
What is SUS316L Stainless Steel?
316L is a grade of stainless steel, belonging to the American ASTM standard system. Its corresponding grade in the Chinese GB standard system is 022Cr17Ni12Mo2, and its unified numerical designation is S31603. 316L austenitic stainless steel has a face-centered cubic crystal structure, is non-magnetic, and cannot be strengthened by heat treatment. Its strength can only be improved by cold working. It has good plasticity and toughness at room and low temperatures, is easy to form, and has good weldability. Its products include plates, bars, pipes, strips, wires, and forgings.
SUS316L Stainless Steel vs. 316：Equivalent Material
| Standard / Region | SUS316L | 316 Equivalent Grades |
|---|---|---|
| Japan (JIS) | SUS316L | SUS316 |
| USA (ASTM / UNS) | ASTM A240 / UNS S31603 | ASTM A240 / UNS S31600 |
| Europe (EN / DIN) | EN 1.4404 | EN 1.4401 |
| China (GB) | 06Cr17Ni12Mo2 | 0Cr17Ni12Mo2 |
| ISO | ISO 3506-1 / 316L | ISO 3506-1 / 316 |
| Other Notes | Low carbon (≤0.03%) for superior weldability and corrosion resistance | Standard 316 (≤0.08% C), good corrosion resistance but slightly higher risk of carbide precipitation |
What is the difference between SUS316 and SUS316L?
The main difference is that SUS316L has a lower carbon content (maximum 0.03%) than SUS316 (maximum 0.08%). This makes SUS316L more resistant to intergranular corrosion and more suitable for welding without post-weld heat treatment, while SUS316 has slightly higher tensile strength.
SUS316 vs. SUS316L Stainless Steel: Chemical Composition
| Element | SUS316 | SUS316L |
|---|---|---|
| Carbon (C) | ≤0.08% | ≤0.03% |
| Chromium (Cr) | 16–18% | 16–18% |
| Nickel (Ni) | 10–14% | 10–14% |
| Molybdenum (Mo) | 2–3% | 2–3% |
| Manganese (Mn) | ≤2% | ≤2% |
| Phosphorus (P) | ≤0.045% | ≤0.045% |
| Sulfur (S) | ≤0.03% | ≤0.03% |
SUS316 vs. SUS316L Stainless Steel: Mechanical Properties
| Property | SUS316 | SUS316L |
|---|---|---|
| Tensile Strength (MPa) | 515 | 485 |
| Yield Strength (MPa) | 205 | 170 |
| Elongation (%) | 40 | 40 |
| Hardness (HRB) | 92 | 90 |
| Corrosion Resistance | High | Higher (especially in welded joints) |
SUS316 vs. SUS316L Stainless Steel: Corrosion Resistance
SUS316L stainless steel exhibits superior corrosion resistance compared to SUS316, particularly in welded structures or highly corrosive environments. The lower carbon content (≤0.03%) minimizes carbide precipitation during welding, significantly reducing intergranular corrosion risk. In saltwater immersion tests, SUS316L maintains pitting resistance equivalent number (PREN) above 24, while standard SUS316 shows slightly lower performance in welded areas, making SUS316L the preferred choice for chemical, marine, and pharmaceutical applications.
SUS316 vs. SUS316L Stainless Steel: Strength
SUS316 stainless steel generally exhibits slightly higher tensile strength than SUS316L due to its higher carbon content, with typical tensile strength of 515–720 MPa and yield strength of 205–290 MPa. In contrast, SUS316L, with lower carbon (≤0.03%), has a tensile strength of 485–690 MPa and yield strength of 170–275 MPa, offering better ductility and weldability. Despite the modest reduction in strength, SUS316L is preferred in applications requiring extensive welding or resistance to intergranular corrosion.
Are SUS316 and SUS316L magnetic?
No, SUS316 and SUS316L are not magnetic in their standard, annealed state because they are austenitic stainless steels. However, they can become slightly magnetic after being subjected to processes like cold working, welding, or significant machining, which can alter their crystal structure.
What is the SUS316 stainless steel price per kg?
SUS316: $3.0–$4.5/kg, SUS316L: $3.5–$5.0/kg, depending on quantity, surface finish, and certification.
If you have any project needs for 316L 1.4404 stainless steel bars, please feel free to place an order. GNEE has a large inventory of popular products for you to choose from. They can be processed into various practical product forms, including plates, coils, pipes, bars, and wires. For detailed chemical composition and free samples, please contact our factory immediately. We offer competitive prices and excellent service.
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