Stainless Steel 321 Seamless Pipes & Tubes
SS 321 (UNS S32100) is a titanium-stabilized austenitic stainless steel designed for continuous service at temperatures between 425C-900C. The titanium addition prevents chromium carbide precipitation, ensuring resistance to intergranular corrosion after high-temperature exposure.
Size Range
1/4" NPS to 10" NPS (6.35mm to 273.1mm OD)
Wall Thickness
SCH 5S to SCH 160
Standards
4 specs
Chemical Composition (% by weight)
| C | Mn | Si | Cr | Ni | Ti | P | S |
|---|---|---|---|---|---|---|---|
| 0.08 max | 2.00 max | 0.75 max | 17.0-19.0 | 9.0-12.0 | 5xC min | 0.045 max | 0.030 max |
Mechanical Properties (Minimum at Room Temperature)
| Tensile Strength | Yield Strength | Elongation | Hardness |
|---|---|---|---|
| 515 MPa min | 205 MPa min | 35% min | 95 HRB max |
Physical Properties - SS 321
| Density | Melting Range | Thermal Conductivity | Electrical Resistivity | Specific Heat | Coeff. of Thermal Expansion |
|---|---|---|---|---|---|
| 7.92 g/cm3 | 1400-1425 C | 16.1 W/m-K | 720 nOhm-m | 500 J/kg-K | 17.2 um/m-C |
Corrosion Resistance - SS 321
| Property | Value |
|---|---|
| Pitting Resistance (PREN) | ~17.5 |
| Max Service Temp (Oxidizing) | 900 C (continuous) |
| Intergranular Corrosion | Resistant (Ti stabilized) |
| Stress Corrosion Cracking | Susceptible in chlorides >60C |
| General Corrosion Rate | <0.1 mm/yr in mild acids |
| Seawater Resistance | Limited |
Equivalent International Grades
| ASTM | JIS | BS | GOST |
|---|---|---|---|
| TP321 | SUS 321 | 321S31 | 08Kh18N10T |
SS 321 vs Comparable Grades
| Grade | UNS | Tensile | Yield | PREN | Max Temp |
|---|---|---|---|---|---|
| SS 304 / 304LAustenitic Stainless Steel | S30400 | 515 / 485 MPa min | 205 / 170 MPa min | ~18 | 870 C |
| SS 347Austenitic Stainless Steel | S34700 | 515 MPa min | 205 MPa min | ~17.5 | 900 C |
| SS 310SAustenitic Stainless Steel | S31008 | 515 MPa min | 205 MPa min | ~25 | 1150 C (intermittent 1035 C continuous) |
Applicable Standards
Applications
Key Advantages of SS 321
SS 321 Applications by Region
Middle East (UAE, Saudi Arabia, Qatar, Oman, Kuwait)
Used in refinery furnace tubes, heat exchangers, and high-temperature process equipment across UAE, Saudi Arabia, and Kuwait refineries.
Europe (Germany, UK, Norway, Netherlands, Italy)
Specified for power plant superheater tubes and petrochemical furnace applications in Germany, UK, and Netherlands.
United States
Standard grade for refinery and petrochemical high-temperature service applications.
Frequently Asked Questions about SS 321 Seamless Pipes
Quick Specifications
1/4" NPS to 10" NPS (6.35mm to 273.1mm OD)
SCH 5S to SCH 160
Industries Served
Related Grades
Compare With
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Heat Exchanger Tubes →Ready to Order SS 321 Seamless Pipes?
Stancor is India's leading manufacturer of SS 321 seamless pipes, exporting to UAE, Saudi Arabia, Qatar, Germany, UK, and USA. Contact our sales team for competitive pricing, fast delivery, and full material certification.