SS 321 — Sheet, Plate, Coil, Pipe & Tube & Fittings
Also sold as AISI 321 · UNS S32100 · W.Nr 1.4541 · Titanium-stabilised stainless
SS 321 is a titanium-stabilised austenitic stainless steel, chosen for high-temperature service between 425 and 815 °C. We supply it as sheet, plate, coil, pipe & tube, fittings, flanges, fasteners, with EN 10204 3.1 certificates, from Mumbai to India, the Gulf, South-East Asia, South America, Europe, the UK and the USA.
- UNS S32100
- W.Nr 1.4541
- PREN ≈ 18
- ρ 7.92 g/cm³
Reviewed by the Kanak Steel & Engineering Co. technical team · Updated October 2026
SS 321 Names, Designations & Composition
SS 321 is one alloy sold under several names. Its UNS number is S32100, the European material number is W.Nr 1.4541 and the EN name is X6CrNiTi18-10. The chart on the right shows the specified range of each main alloying element; the balance is the base metal.
SS 321 Specifications by Product — Which Standard Applies?
The material standard changes with the product form. This is the table buyers ask for most.
| Product | Material standard | Dimensions |
|---|---|---|
| SS 321 sheet | ASTM A240 | ASTM A480 / B906 |
| SS 321 plate | ASTM A240 | ASTM A480 / B906 / A20 |
| SS 321 coil | ASTM A240 | ASTM A480 |
| SS 321 pipe & tube | ASTM A312 TP321 · ASTM A312 · A358 | ASME B36.19 / B36.10 |
| SS 321 fittings | ASTM A403 WP321 · ASTM A182 F321 | ASME B16.9 · B16.11 |
| SS 321 flanges | ASTM A182 F321 | ASME B16.5 · B16.47 |
| SS 321 fasteners | ASTM A193 B8T | ASME B18.2.1 · B18.2.2 |
SS 321 Chemical Composition
Under technical review for TDS.
| Element | Current requirement |
|---|---|
| Chromium | As specified |
| Nickel | As specified |
| Titanium | As specified |
| Carbon | As specified |
| Manganese | As specified |
| Silicon | As specified |
| Nitrogen | As specified |
| Phosphorus | As specified |
| Sulphur | As specified |
| Iron | As specified |
Numerical specification requirements are published only after the applicable current standard edition has been verified. Governing specification to be verified: ASTM A240 for UNS S32100.
SS 321 Mechanical Properties
Under technical review for TDS.
| Property | Current requirement |
|---|---|
| Tensile strength | As specified |
| Yield strength 0.2% | As specified |
| Elongation | As specified |
| Hardness | As specified |
Numerical specification requirements are published only after the applicable current standard edition has been verified. Governing specification and condition to be verified: ASTM A240 for UNS S32100 — Annealed plate & sheet.
Density & Physical Properties
| Property | Value |
|---|---|
| Density | 7.92 g/cm³ |
| Melting range | 1400 – 1425 °C |
| Magnetic | Non-magnetic annealed |
| PREN (approx.) | ≈ 18 |
SS 321 Equivalent Grades
SS 321 Corrosion Resistance — What Each Element Does
About 18% chromium forms the passive film that makes the steel stainless.
Nickel keeps the structure austenitic — tough at low temperature and easy to form and weld.
Titanium ties up carbon, so 321 keeps its corrosion resistance after long service in the sensitising range.
321H with higher carbon is used above about 540 °C for better creep strength.
SS 321 vs 304, 347 and 310S
| Grade | PREN (approx.) | Pick it for |
|---|---|---|
| SS 304 | ≈ 18 | General corrosion resistance, food, water and architectural work |
| SS 347 | ≈ 18 | Welded high-temperature piping in refineries and power plants |
| SS 321 | ≈ 18 | High-temperature service between 425 and 815 °C |
| SS 310 / 310S | ≈ 25 | Furnaces, burners and heat treatment at high temperature |
Welding SS 321
| Matching filler | ER347 (AWS A5.9) |
|---|---|
| Also used | ER321 is rare; ER347 is the usual filler |
SS 321 for export
FOB / CIF · Nhava Sheva (JNPT), MumbaiSS 321 — questions buyers ask
What is SS 321?
SS 321 is a titanium-stabilised austenitic stainless steel. It is chosen for high-temperature service between 425 and 815 °C.
Which standards cover SS 321 products?
Sheet: ASTM A240; Plate: ASTM A240; Coil: ASTM A240; Pipe & Tube: ASTM A312 TP321 · ASTM A312 · A358; Fittings: ASTM A403 WP321 · ASTM A182 F321; Flanges: ASTM A182 F321; Fasteners: ASTM A193 B8T. Always name the standard and edition on your order.
What is the UNS number of SS 321?
UNS S32100 · S32109 (321H), with the European material number W.Nr 1.4541.
What is the density of SS 321?
7.92 g/cm³ — use it to calculate weights: plate kg = L(m) × W(m) × t(mm) × 7.92.
SS 321 or SS 310 / 310S?
SS 321 suits high-temperature service between 425 and 815 °C; SS 310 / 310S is the step up for furnaces, burners and heat treatment at high temperature.
Sources: the ASTM / ASME specifications named on this page and producer datasheets · Last updated October 2026