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Mineral Insulated Thermocouples | Pyrosales


The metal sheathed mineral insulated thermocouple has become the accepted norm in most industries.

Price Guide: POA

It features a variety of temperature and corrosion resistant sheaths and extremely high purity (96% or better) magnesium oxide (MgO) insulation.

The information below provides a selection guide for Mineral Insulated Thermocouple Sheathing Material:

  • 304SS     
    • Maximum temperature: 900°C.
    • Most widely used low temperature sheath material.
    • Extensively used in food, beverage, chemical and other industries where corrosion resistance is required.
    • Subject to damaging carbide precipitation in 480 to 870°C range.
    • Lowest cost corrosion resistant sheath material available.
  • 321SS
    • Maximum temperature: 870°C.
    • Similar to 304SS except titanium stabilised for inter-granular corrosion. This alloy is designed to overcome susceptibility to carbon precipitation in the 480 to 870° C range.
    • Used in aerospace and chemical applications.
  • 316SS
    • Maximum temperature: 900°C.
    • Best corrosion resistance of the austenitic stainless steel grades.
    • Widely used in the food and chemical industry.
    • Subject to damaging carbide precipitation in 482 to 870°C range.
  • 347SS
    • Maximum temperature: 870°C.
    • Similar to 304 SS except nickel niobium stabilised. This alloy is designed to overcome susceptibility to carbide precipitation in the 480 to 870°C range.
    • Used in aerospace and chemical applications.
  • 310SS
    • Maximum temperature: 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 304SS.
  • 446SS
    • Maximum temperature: 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.
  • INCONEL® 600
    • Maximum temperature: 1150°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: 1205°C.
    • Widely used in aerospace applications.
    • Resistant to oxidising, reducing and neutral atmospheric conditions.
    • Excellent high temperature strength along with superior oxidation resistance.
    • Resistant to stress corrosion cracking in petrochemical applications.
    • Maximum temperature 1175°C.
    • Developed to provide superior sulfidation-resistance at high temperatures. This alloy shows good resistance to corrosion in some salt bath applications.
    • Applications include sulfur furnaces, waste incinerators, coke burners, recuperators, cement kilns and high temperature furnaces.
    • Maximum temperature 1250°C.
    • Better oxidation resistance than Inconel®; other characteristics as Inconel.
    • Used in heat treatment furnaces, glass industry, ceramic manufacture, aluminium production.
  • PLATINUM 10% Rh
    • Maximum temperature: 1500°C.
    • Excellent oxidation resistance.
    • Used in glass manufacturing, gas turbine testing and research. Type 'R', 'S', 'B' only.
    • Composite-sheathed thermocouples provide the user with an economical alternative to a full 10%Rh sheath where only the hot end of the thermocouple is sheathed as precious metal, the balance is replaced by Inconel®.

Inconel® is a registered trademark of the International Nickel Co.
Hastelloy® is a registered trademark of Haynes International.