Kanthal AF is a high-temperature ferritic iron-chromium-aluminium alloy (FeCrAl alloy) with excellent oxidation resistance and service life in combination with good form stability properties. It is suitable for use at temperatures up to 1300°C (2370°F).
Kanthal AF is typically used in electrical heating elements in industrial furnaces and in the appliance industry.
Example of applications in the appliance industry are in open mica elements for toasters, hair dryers, in meander shaped elements for fan heaters and as open coil elements on fibre insulating material in ceramic glass top heaters in ranges, in ceramic heaters for boiling plates, coils on molded ceramic fibre for cooking plates with ceramic hobs, in suspended coil elements for fan heaters, in suspended straight wire elements for radiators, convection heaters, in porcupine elements for hot air guns, radiators, tumble dryers.
Chemical composition
| C % |
Si % |
Mn % |
Cr % |
Al % |
Fe % |
| Nominal composition |
5.3 |
Bal. |
| Min |
- |
- |
- |
20.5 |
- |
| Max |
0.08 |
0.7 |
0.4 |
23.5 |
- |
Mechanical properties
| Wire size |
Yield strength |
Tensile strength |
Elongation |
Hardness |
| Ø |
Rp0.2 |
Rm |
A |
| mm |
MPa |
MPa |
% |
Hv |
| 1.0 |
500 |
700 |
23 |
230 |
| 4.0 |
475 |
680 |
18 |
230 |
Mechanical properties at elevated temperature
| Temperature °C |
900 |
1000 |
1100 |
1200 |
1300 |
| MPa |
37 |
20 |
12 |
6 |
4 |
Ultimate tensile strength - deformation rate 6.2 x 10-2 /min
Creep strength - 1% elongation in 1000 h
| Temperature °C |
1100 |
1200 |
| MPa |
1.7 |
0.3 |
Physical properties
| Density g/cm3 |
7.15 |
| Electrical resistivity at 20°C Ω mm2/m |
1.39 |
| Poisson's ratio |
0.30 |
Young's modulus
| Temperature °C |
20 |
100 |
200 |
400 |
600 |
800 |
1000 |
| GPa |
220 |
210 |
205 |
190 |
170 |
150 |
130 |
Temperature factor of resistivity
| Temperature°C |
100 |
200 |
300 |
400 |
500 |
600 |
700 |
800 |
900 |
1000 |
1100 |
1200 |
1300 |
| Ct |
1.00 |
1.01 |
1.01 |
1.02 |
1.03 |
1.04 |
1.04 |
1.05 |
1.05 |
1.06 |
1.06 |
1.06 |
1.06 |
Coefficient of thermal expansion
| Temperature °C |
Thermal Expansion x 10-6/K |
| 20 - 250 |
11 |
| 20 - 500 |
12 |
| 20 - 750 |
14 |
| 20 - 1000 |
15 |
Thermal conductivity
| Temperature °C |
50 |
600 |
800 |
1000 |
1200 |
| W m-1 K-1 |
11 |
20 |
22 |
26 |
27 |
Specific heat capacity
| Temperature °C |
20 |
200 |
400 |
600 |
800 |
1000 |
1200 |
| kJ kg-1 K-1 |
0.46 |
0.56 |
0.63 |
0.75 |
0.71 |
0.72 |
0.74 |
| Melting point °C |
1500 |
| Max continuous operating temperature in air °C |
1300 |
| Magnetic properties |
The material is magnetic up to approximately 600°C (Curie point). |
| Emissivity - fully oxidized material |
0.70 |
Disclaimer: Recommendations are for guidance only, and the suitability of a material for a specific application can be confirmed only when we know the actual service conditions. Continuous development may necessitate changes in technical data without notice. This datasheet is only valid for Kanthal materials.