SUS321 Stainless Steel: Composition, Properties and Applications
Aug 15, 2025
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Compared with SUS304, SUS321 offers improved creep strength and resistance to carbide precipitation, thanks to the titanium addition - a reliable option for high-temperature piping systems, exhaust manifolds and pressure vessels.
Chemical Composition of SUS321 Stainless Steel
| Element | Composition (%) |
|---|---|
| Carbon (C) | ≤0.08 |
| Silicon (Si) | ≤1.00 |
| Manganese (Mn) | ≤2.00 |
| Phosphorus (P) | ≤0.045 |
| Sulfur (S) | ≤0.030 |
| Chromium (Cr) | 17.00-19.00 |
| Nickel (Ni) | 9.00-12.00 |
| Titanium (Ti) | ≥5 x C% and ≤0.70 |
Mechanical Properties of SUS321 Stainless Steel
| Property | Metric | Imperial |
|---|---|---|
| Tensile strength (min) | 515 MPa | 74.7 ksi |
| Yield strength (min, 0.2% offset) | 205 MPa | 29.7 ksi |
| Elongation (min) | 40% | 40% |
| Hardness (max) | 217 HB (bar/tube form) | - |
| Density | 7.93 g/cm3 | 0.286 lb/in3 |
| Melting range | 1400-1425 C | 2550-2600 F |
Note: for plate product per JIS G4304, the hardness limit is 187 HB - confirm the hardness requirement for the specific product form.
Physical Properties of SUS321 Stainless Steel (UNS S32100 / W.Nr.1.4541)
| Property | Value |
|---|---|
| Density | 7.93 g/cm³ |
| Melting Point | 1398‑1427 °C |
| Modulus of Elasticity | 193 GPa @20 °C |
| Thermal Conductivity | 16.3 W/(m·K) @20 °C |
| Mean Coefficient of Thermal Expansion (20‑300 °C) | 16.6 ×10⁻⁶ /°C |
| Specific Heat Capacity | 500 J/(kg·K) @20 °C |
| Electrical Resistivity | 0.72 μΩ·m @20 °C |
| Magnetic Property | Non‑magnetic (annealed); slight magnetism after cold working |
Typical Applications of SUS321 Stainless Steel
Chemical processing equipment - reactors, heat exchangers, piping.
Petrochemical plants - refinery heater tubes, high-temperature ducts.
Automotive and aerospace exhaust systems.
Boiler and superheater tubing.
Food processing machinery (high-heat sterilization processes).
Expansion joints and bellows.
Heating furnace piping
Chemical plant piping
Food and Pharmaceutical Pipeline
Exporter of SUS321 Stainless Steel
GNEE is a professional exporter of SUS321 (UNS S32100 / W.Nr.1.4541) titanium‑stabilized austenitic stainless steel. We supply seamless & welded pipes, plates, coils and bars complying with ASTM A312, ASTM A240, EN and JIS standardsGNEE. With titanium addition, grade 321 resists intergranular corrosion after welding, widely used for boilers, heat exchangers and high‑temperature exhaust piping. Each batch is supplied with EN10204‑3.1 MTC. PMI, hydrostatic and NDT tests are available, as well as third‑party inspection by SGS / BV / TÜV. We offer cut‑to‑length, beveling and other secondary processing, free samples and seaworthy export packaging. Both small and bulk orders are accepted, products exported to more than 60 countries worldwideGnee Steel.
SUS321 Stainless steel plates
SUS321 stainless steel pipes
SUS321 stainless steel coils
If you need stainless steel that withstands high temperatures, high-frequency welding, and intergranular corrosion, SUS321 stainless steel is your ideal choice. Its high mechanical strength, oxidation resistance, and durability make it widely used in industrial thermal environments.
Contact us today to order SUS321 seamless pipe, welded pipe, and plate-all manufactured to ASTM, JIS, and EN standards and backed by comprehensive mill-test certification.Email: sales@gneestainless.com
FAQ
Both grades are titanium‑stabilized. 321H has higher carbon content for improved high‑temperature creep strength for long‑term hot piping. Standard 321 has lower carbon for general high‑temperature applications.
321 relies on titanium for intergranular‑corrosion resistance. 316L uses low carbon plus molybdenum for chloride resistance. 304 lacks stabilizing elements and is prone to intergranular corrosion after high‑temperature welding. Choose 321 for high‑temperature service; select 316L for chloride‑containing environments.
SUS321 is generally non‑magnetic in solution‑annealed condition. Slight magnetism may appear after cold working, bending or stretching. This is normal for austenitic steel and does not indicate material defect.
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