We manufacture welded 321 stainless steel tube from 6mm to 63.5mm OD, 0.4mm to 2mm wall thickness, to ASTM A249, A269, and A213 standards.
We manufacture welded 321 stainless steel tube from 6mm to 63.5mm OD, 0.4mm to 2mm wall thickness, to ASTM A249, A269, and A213 standards. 321 is titanium-stabilized, which prevents chromium carbide precipitation (sensitization) during welding and sustained exposure to 427–816°C — making it the preferred grade for welded tube that must perform reliably at high temperature, rather than just resist general corrosion.
| Element | Value |
|---|---|
| Chromium (Cr) | 17.0–19.0 |
| Nickel (Ni) | 9.0–12.0 |
| Titanium (Ti) | ≥5× Carbon content (min), ≤0.70 max |
| Carbon (C) | ≤0.08 |
| Manganese (Mn) | ≤2.00 |
| Silicon (Si) | ≤1.00 |
| Phosphorus (P) | ≤0.045 |
| Sulfur (S) | ≤0.030 |
| Iron (Fe) | Balance |
| Property | Value |
|---|---|
| Tensile strength | ≥515 MPa |
| Yield strength (0.2%) | ≥205 MPa |
| Elongation | ≥40% |
| Density | 8.0 g/cm³ |
Figures shown are standard reference values for this grade; exact limits are governed by the applicable ASTM/ASME specification on your order and Mill Test Certificate.
When standard austenitic grades like 304 are welded and later exposed to sustained heat, chromium can combine with carbon at the grain boundaries (sensitization), reducing corrosion resistance right at the weld. Titanium in 321 preferentially bonds with carbon instead, protecting the weld zone — which is exactly why 321 is specified for high-temperature welded tube rather than 304 or 316.
| 304 | 321 | |
|---|---|---|
| Stabilization | None | Titanium |
| Best for | General-purpose, moderate temperature | Sustained high-temperature welded service |
| Cost | Lower | Higher |
In short: if your application involves welding followed by sustained exposure above ~400°C, 321 protects weld-zone corrosion resistance in a way 304 does not.
Grade, size, standard, quantity — send what you have and we'll respond with availability, lead time and pricing.