Which grade for an oxygen sensor housing?
310S when the housing sits on the exhaust side and has to survive repeated high-temperature cycling without scaling; 304 where the housing is shielded from the hot gas path or runs at moderate temperature. The decision is about oxidation resistance, not about corrosion in a liquid.
| 304 / 304L | 310S | |
|---|---|---|
| Position in the exhaust | Shielded or moderate-temperature locations | Directly in the hot gas path, cycled repeatedly |
| Oxidation / scaling | Scales when held hot; not an exhaust-side grade | Designed for high-temperature oxidation resistance |
| Drawability | The easier grade to form | Work-hardens hard; more stages or intermediate anneals |
| Tooling impact | Reference tooling and lubrication | Tool material, clearance and lubrication chosen for the grade |
| Cost | Lower | Higher material cost and slower forming |
| Typical use here | Fitments, shields, dry-side housings | O2, NOx and exhaust temperature sensor housings |
Published configurations
| Grade | Configurations | Height range (mm) | OD range (mm) |
|---|---|---|---|
| SUS 304 | 47 | 0.1-48.5 | 9.10-80.00 |
| SUS 310 | 127 | 0.9-54.0 | 0.70-16.70 |
310S is the most used grade in the catalogue (127 of 398 configurations), which reflects how much of the range is exhaust-side sensor work.
What to put on the drawing
- Maximum continuous temperature and the thermal cycling pattern.
- Whether the housing is in the gas path or shielded - the same part in a different location changes the grade decision.
- Wall thickness and sealing-face tolerance, because 310S holds them differently from 304.
- Any magnetic requirement, which would rule both grades out in favour of a ferritic grade such as 430.
If the answer is not obvious from the drawing alone, send it with the application temperature and the DFM review will say which grade the forming route can hold and what it does to tooling life.