Materials for thermowells and temperature sensors
The maximum temperature in the table applies to the material in air. Medium, pressure and the required service life can lower it considerably — sulphurous or carburising atmospheres, for example, substantially.
Everything listed here we process ourselves. Further materials, 3.1 material test certificates to EN 10204 and coatings of ECTFE, PFA, tantalum or Stellite on request.
Maximum temperature in air. Medium, pressure and the required service life can lower it considerably.
Stainless steel
| Material no. | Short name EN | ASTM / UNS | max. temperature | typical use |
|---|---|---|---|---|
| 1.4571 | X6CrNiMoTi17-12-2 | 316Ti | +600 °C | standard for thermowells and sheaths |
| 1.4404 | X2CrNiMo17-12-2 | 316L | +550 °C | pharmaceuticals, food, weldable |
| 1.4435 | X2CrNiMo18-14-3 | 316L | +550 °C | pharmaceuticals, increased corrosion resistance |
| 1.4541 | X6CrNiTi18-10 | 321 | +600 °C | general plant engineering |
| 1.4301 | X5CrNi18-10 | 304 | +550 °C | standard stainless steel, housings and sleeves |
| 1.4305 | X8CrNiS18-9 | 303 | +400 °C | free-cutting steel for turned and connection parts |
| 1.4539 | X1NiCrMoCu25-20-5 | 904L | +400 °C | acids, chlorides |
| 1.4462 | X2CrNiMoN22-5-3 | Duplex | +300 °C | high strength and pitting resistance |
Heat-resistant
| Material no. | Short name EN | ASTM | max. temperature | typical use |
|---|---|---|---|---|
| 1.4762 | X10CrAlSi25 | 446 (comparable) | +1,200 °C | scale-resistant thermowells, sulphurous atmosphere |
| 1.4841 | X15CrNiSi25-21 | 314 | +1,150 °C | support tubes, furnace construction |
| 1.4749 | X18CrNi28 | 446 | +1,150 °C | high temperature, sulphurous atmosphere |
| 1.4876 | X10NiCrAlTi32-20 | Alloy 800 | +1,100 °C | high temperature, carburisation |
| Kanthal | FeCrAl | – | +1,250 °C | highest scale resistance, furnaces and melting plants |
Nickel-based alloys
| Material no. | Short name | max. temperature | typical use |
|---|---|---|---|
| 2.4816 | Alloy 600 / Inconel 600 | +1,150 °C | mineral-insulated thermocouples, thermowells |
| 2.4610 | Alloy C4 | +1,000 °C | strongly corrosive media |
| 2.4602 | Alloy C22 | +1,000 °C | oxidising and reducing media |
| 2.4819 | Alloy C276 | +1,000 °C | chemicals, chlorides |
| 2.4856 | Alloy 625 | +1,000 °C | seawater, high strength |
Steel, special materials and ceramics
| Material | Short name | max. temperature | typical use |
|---|---|---|---|
| 1.0460 | P250GH / A105 | +450 °C | steam and pressure lines |
| 3.7035 | Titanium grade 2 | +300 °C | chlorides, seawater |
| Tantalum | F560 | +250 °C | sleeves and coatings for acids |
| C610 | Mullite, approx. 60 % Al₂O₃ | +1,500 °C | thermowells for furnaces, resistant to thermal shock |
| C799 | Alumina, 99.7 % Al₂O₃ | +1,600 °C | gas-tight, for noble-metal thermocouples |
How we choose the material
- Temperature first, but with reserve: continuous operation at the top end of the table costs service life.
- Sulphur largely rules out nickel-based alloys — then 1.4762 or 1.4749.
- Carburising atmosphere speaks for Alloy 800 / 1.4876.
- Chlorides and acids lead to 904L, Alloy C276 or tantalum.
- Flow and pressure decide the wall thickness — and belong in the thermowell calculation, not in the choice of material alone.
Material unclear?
Send us the medium, concentration, temperature and flow velocity — we will propose the material and the wall thickness.
Question about the design?
Tell us the medium, temperature and installation situation — you will have a proposal within one working day.