Thermocouple Sheath Material
Thermocouple Sheath Material Temperature Limit
Specific Temperature Limits:
316 Stainless Steel
- Maximum temperature: 1650. Best corrosion resistance of the austenitic stainless steel grades. Widely used in the food and chemical
- industry. Subject to damaging carbide precipitation in 900F to 1600F (482C to 870C).
- Maximum temperature: 1650°F (900°C). Same as 316 SST (04) except Iow carbon version allows for better welding and febrication.
- Maximum temperature: 1650°F (900°C). Most widely used low temperature sheath material. Extensively used in food, beverage, chemical and other industries where corrosion resistance is required.
- Industry: Subject to damaging carbide precipitation in 900 to 1600°F (480 to 870°C) range. Lowest cost corrosion resistant sheath material available.
304L Stainless Steel
- Maximum temperature: 1650°F (900°C). Low carbon version of 304 SST (02). Low carbon content allows this material to be welded and heated in the 900 to 1600°F (480 to 870°C) range without damage to corrosion resistance.
310 Stainless Steel
- Maximum temperature: 2100°F (1150°C). Mechanical and corrosion resistance, similar to but better than 304 SS. Very good heat resistance.
- This alloy contains 25% chromium, 20% nickel. Not as ductile as 304 SS.
321 Stainless Steel
- Maximum temperature: 1600°F (870°C). Similar to 304 SS except titanium stabilized for intergranular corrosion.
- This alloy is designed to overcome susceptibility to carbon precipitation in the 900 to 1600°F (480 to 870°C) range. Used in aerospace and chemical applications.
446 Stainless Steel
- Maximum temperature: 2100°F (1150°C). Ferritic stainless steel which has good resistance to sulfurous atmospheres at high temperatures.
- Good corrosion
resistance to nitric acid, sulfuric
acid and most alkalies. 27% chromium
content gives this alloy the highest heat
resistance of any ferritic stainless steel
- Maximum temperature: 2150°F (1175°C). Most widely used thermocouple sheath material. Good high temperature strength, corrosion resistance, resistance to chloride-ion stress corrosion cracking and oxidation resistance to high temperatures.
- Do not use in sulfur bearing environments. Good in nitriding environments.
- Maximum temperature: 2150°F (1175°C) continuous, 2300°F (1260°C) intermittent. Similar to Alloy 600 with the addition of aluminum for outstanding oxidation resistance. Designed for high temperature corrosion resistance.
- This material is good in carburizing environments, and has good creep rupture strength. Do not use in vacuum furnaces! Susceptible to intergranular attack by prolonged heating in 1000 to 1400°F (540 to 760°C) temperature range.
- Maximum temperature: 2000°F (1095°C). Widely used as heater sheath material. Minimal use in thermocouples. Superior to Alloy 600 in sulfur, cyanide salts and fused neutral salts.
- Susceptible to intergranular attack in some applications by exposure to the temperature range of 1000 to 1400°F (540 to 760°C).