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Protection Sheath Material Datasheets
Materials specification for temperature sensor protection sheaths
Our temperature sensors are specifically designed for many different types of harsh and reducing atmosheres and therefore we supply protection sheaths suitable for each application. Here is a list of datasheets for the materials that we supply and use.
Mild Steel
Ceramic support tube (Plated) Occasional sensor protection use
| Basic Composition | Fe, C |
| Temperature Limits | 550 ° C |
| International Standards | Seamless Pipe |
| Density | 7.9 g/cm³ |
| Melting Range | |
| Specific Heat | |
| Coefficient of Expansion | |
| Thermal Conductivity | |
| Peak Sensors Colour Code | Black |
446, 4C54, Ferritic
Very good resistance to sulphurous gases and salts. Good resistance to oxidation in air. Good resistance to oil ash corrosion, molten copper, lead, tin. In sulphurous reducing atmosphere 446 performs better than austenitic steels, although Nitrogen concentrations can result in early failure. Hot gases containing hydrocarbons and carbon monoxide can cause carburisation, if oxygen is present for an oxide layer to form 446 performs well, otherwise failure occurs quickly.
| Basic Composition | Cr 26.5%, Mn 0.8%, Si 0.5%, N 0.2%, C 0.2% Max, P 0.03 Max, S 0.15 Max, Bal Fe |
| Temperature Limits | 1100 ° C in air and oxidising conditions |
| International Standards | 1.4749, 446-1 |
| Density | 7.6 g/cm³ |
| Melting Range | |
| Specific Heat | 460 rising to 670 J/Kg ° C |
| Coefficient of Expansion | 13.5 x10-6 / ° C |
| Thermal Conductivity | 17 rising to 28 W/m ° C |
| Peak Sensors Colour Code | Blue |
Kanthal AF, Kanthal APM
High resistance to attack by sulphur. Resists carburisation at temperature. Very little scaling reduces furnace contamination. Better heat transfer than ceramic.
| Basic Composition | Cr 22%, Al 4-6%, Fe Balance. |
| Temperature Limits | 1400 ° C |
| International Standards | |
| Density | 7.1 g/cm³ |
| Melting Range | |
| Specific Heat | |
| Coefficient of Expansion | 12 rising to 16 x10-6 / ° C |
| Thermal Conductivity | 12 rising to 32 W/m ° C |
| Peak Sensors Colour Code |
Kanthal Super
Less brittle than ceramics. Excellent in corrosive furnaces. Suppresses electromagnetic oscillations.
| Basic Composition | Moloybdenum disilicade MoSi 2 |
| Temperature Limits | 1700 ° C |
| International Standards | |
| Density | |
| Melting Range | |
| Specific Heat | |
| Coefficient of Expansion | |
| Thermal Conductivity | |
| Peak Sensors Colour Code |
Cast Iron
Inexpensive material used in molten aluminium. It has a relatively short life due to oxidation but other materials also have their drawbacks in this application. Brittle metal.
| Basic Composition | Fe, C (3 to 3.5%) |
| Temperature Limits | 900 ° C in Aluminium |
| International Standards | |
| Density | 7.9 g/cm³ |
| Melting Range | |
| Specific Heat | |
| Coefficient of Expansion | |
| Thermal Conductivity | |
| Peak Sensors Colour Code |