SS316L vs SUS316L Stainless Steel: What's the Difference?
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SS316L vs SUS316L Stainless Steel: What's the Difference?
SS316L and SUS316L are essentially the same material: a low-carbon version of 316 stainless steel, with the "L" signifying lower carbon (max 0.03%) for superior weldability and corrosion resistance, especially after welding, while "SS" and "SUS" are just regional/standards prefixes (Stainless Steel vs. Japanese Industrial Standards), with SS316L often used in the West and SUS316L in Japan/Asia, both ideal for welded structures like pressure vessels, chemical piping, and medical equipment.
What is SS316L material?
316L stainless steel is a low-carbon, molybdenum-containing austenitic stainless steel known for its excellent corrosion resistance, especially against chlorides and acids, making it ideal for marine, chemical, and medical applications; the "L" signifies low carbon, improving weldability and resistance to sensitization (grain boundary corrosion) compared to standard 316 steel, while still offering toughness and formability.
What is SUS316L material?
SUS316L is a high-grade, low-carbon austenitic stainless steel (JIS standard) renowned for superior corrosion resistance, especially against chlorides and pitting, thanks to added molybdenum, making it ideal for marine, medical, food processing, and heavy welded applications where intergranular corrosion is a concern. The "L" signifies its low carbon content (max 0.03%), improving weldability compared to standard 316 stainless steel.
1. Standards Definition: SS316L vs SUS316L
The primary difference between SS316L and SUS316L lies in standards designation, not in fundamental metallurgy.
| Designation | Standard System | Governing Standard |
|---|---|---|
| SS316L | ASTM / AISI (International / US-based) | ASTM A240 / A276 / A312 |
| SUS316L | JIS (Japanese Industrial Standards) | JIS G4304 / G4305 |
2.SS316L vs SUS316L：Chemical Composition
The addition of 2–3% molybdenum is the key factor that gives both SS316L and SUS316L superior pitting and crevice corrosion resistance compared with 304/304L, especially in chloride-rich environments.
| Element | SS316L (ASTM A240) | SUS316L (JIS G4304) |
|---|---|---|
| Carbon (C) | ≤ 0.03 | ≤ 0.03 |
| Chromium (Cr) | 16.0 – 18.0 | 16.0 – 18.0 |
| Nickel (Ni) | 10.0 – 14.0 | 10.0 – 14.0 |
| Molybdenum (Mo) | 2.0 – 3.0 | 2.0 – 3.0 |
| Manganese (Mn) | ≤ 2.0 | ≤ 2.0 |
| Silicon (Si) | ≤ 0.75 | ≤ 1.00 |
| Phosphorus (P) | ≤ 0.045 | ≤ 0.045 |
| Sulfur (S) | ≤ 0.03 | ≤ 0.03 |
3.SS316L vs SUS316L：Mechanical Properties
In practical engineering applications, the mechanical performance of SS316L and SUS316L is functionally the same.
| Property | SS316L | SUS316L |
|---|---|---|
| Tensile Strength | ≥ 485 MPa | ≥ 480 MPa |
| Yield Strength (0.2%) | ≥ 170 MPa | ≥ 170 MPa |
| Elongation | ≥ 40% | ≥ 40% |
| Hardness | ≤ 95 HRB | ≤ 95 HRB |
Corrosion resistance of SUS316L stainless steel
SUS316L stainless steel offers excellent corrosion resistance due to its 16–18% chromium and 2–3% molybdenum content, providing strong protection against pitting and crevice corrosion in chloride-containing environments such as seawater and chemical processing systems.
Weldability of SUS316L stainless steel
With a low carbon content of ≤ 0.03%, SUS316L stainless steel exhibits excellent weldability, significantly reducing the risk of intergranular corrosion in the heat-affected zone after welding, even without post-weld heat treatment.
What is the density of SUS316L stainless steel?
The density of SUS316L stainless steel is approximately 7.98 g/cm³ (7,980 kg/m³), which is consistent with other austenitic stainless steels in the 316L family.
Is SUS316L stainless steel magnetic?
SUS316L stainless steel is essentially non-magnetic in the annealed condition, although slight magnetism may develop after cold working or forming due to partial transformation of austenite.
Is SUS316L stainless steel food-grade stainless steel?
Yes, SUS316L stainless steel is widely recognized as a food-grade stainless steel because its low carbon content and molybdenum addition provide excellent resistance to acidic foods, chlorides, and frequent cleaning cycles, meeting common food-contact requirements.
What are the differences between SUS316L and SUS316 stainless steel?
The main difference is carbon content: SUS316L contains ≤ 0.03% carbon, while SUS316 allows up to 0.08%, making SUS316L superior in weldability and resistance to intergranular corrosion, especially in welded structures.
Supply and Customization Services for SS316L / SUS316L Products
Available Product Forms
SS316L and SUS316L stainless steel is typically supplied in the following forms: sheets, coils and strips, tubes (seamless/welded), bars, and custom-fabricated parts.
Typical Specifications
Thickness: 0.3 mm – 50 mm (customizable)
Width/Length: Cut to size
Surface Finish: 2B, BA, No.1, No.4, HL, Mirror finish
Standards: ASTM, AISI, JIS, EN, DIN
Processing Services: Laser cutting/plasma cutting, bending and forming, welding and fabrication, drilling/punching
Certification and Quality Control: Mill Test Certificate (EN 10204 3.1), ISO certified production, third-party inspection available (SGS, BV, TUV)
