321 Stainless (UNS S32100)
Titanium-stabilised austenitic stainless for welded assemblies in the 425–815 °C sensitisation range.
- UNS
- S32100
- W.Nr / EN
- 1.4541
- Density
- 7.9 g/cm³
- Service range
- To ~815 °C (scaling ~900 °C intermittent)
About 321 Stainless
321 is 18/8 austenitic stainless steel stabilised with titanium, which ties up carbon and prevents chromium-carbide sensitisation during welding or long service between about 425 and 815 °C. That makes it the standard austenitic grade for hot, welded hardware that plain 304 would fail through intergranular attack.
It retains good strength and oxidation resistance to about 815 °C in continuous service. DMK Alloys supplies 321 as bars, blanks and sheet-route components for exhaust and hot-air systems.
321 Stainless chemical composition (weight %)
| Element | Limit / range |
|---|---|
| Fe | Balance |
| Cr | 17.0 – 19.0 |
| Ni | 9.0 – 12.0 |
| Ti | 5×(C+N) – 0.70 |
| C | ≤ 0.08 |
| Mn | ≤ 2.0 |
| Si | ≤ 0.75 |
| P | ≤ 0.045 |
| S | ≤ 0.03 |
| N | ≤ 0.10 |
Composition limits per the commonly referenced standards listed below. Order-specific limits may differ — confirm against the governing specification.
321 Stainless mechanical properties (typical)
| Condition / form | Tensile, MPa | 0.2% Yield, MPa | Elongation, % |
|---|---|---|---|
| Bar / plate, annealed, room temp. | ≥ 515 | ≥ 205 | ≥ 40 |
Values are typical or specification-minimum levels for guidance only — not a guarantee of properties. Certified values are established by testing against the ordered specification.
321 Stainless specifications & international equivalents
| System | Designation | Covers |
|---|---|---|
| UNS | S32100 | All product forms |
| AMS | AMS 5510 | Sheet, strip, plate |
| AMS | AMS 5645 | Bars, forgings |
| ASTM | ASTM A240 | Plate, sheet, strip |
| ASTM | ASTM A276 | Bars, shapes |
| W.Nr / EN | 1.4541 · X6CrNiTi18-10 | European cross-reference |
Cross-references are for guidance; the governing document is always the specification cited on your purchase order or drawing.
321 Stainless physical properties
| Property | Typical value |
|---|---|
| Density | 7.9 g/cm³ |
| Melting range | 1400 – 1425 °C |
| Modulus of elasticity (family-typical) | ≈ 190 – 210 GPa |
| Indicative service range | To ~815 °C (scaling ~900 °C intermittent) |
Forms we manufacture
- Bars
- Sheet and plate blanks
- Fabricated components to drawing
Dimensional ranges and delivery conditions are confirmed per enquiry.
Where 321 Stainless earns its keep
Typically specified for:
- Exhaust manifolds
- Stacks
- Expansion joints
- Boiler casings
- Welded hot-air ducting
Also consider
Alloy 600
UNS N06600 · W.Nr 2.4816AMS 5665 · AMS 5540
The base nickel–chromium–iron engineering alloy: oxidation and chloride-cracking resistance across a very wide temperature span.
17-4PH Stainless
UNS S17400 · W.Nr 1.4542AMS 5643 · AMS 5604
Martensitic precipitation-hardening stainless steel — high strength and corrosion resistance from a single low-distortion age.
15-5PH Stainless
UNS S15500 · W.Nr 1.4545AMS 5659 · ASTM A564 XM-12
The ferrite-free refinement of 17-4PH: better transverse toughness for critical forged and premium-melted parts.
Request 321 Stainless to your specification
State the governing standard, form, dimensions, quantity and testing requirements — the export team responds with a manufacturer's quotation.