Kanthal® A-1 is a ferritic iron-chromium-aluminium alloy (FeCrAl alloy) for use at temperatures up to 1400°C (2550°F). The alloy is characterized by high resistivity and very good oxidation resistance.
Typical applications for Kanthal® A-1 are electrical heating elements in high-temperature furnaces for heat treatment, ceramics, glass, steel, and electronics industries.
Chemical composition
| C % | Si % | Mn % | Cr % | Al % | Fe % | |
|---|---|---|---|---|---|---|
| †Nominal composition | 5.8 | Bal. | ||||
| Min | - | - | - | 20.5 | - | |
| Max | 0.08 | 0.7 | 0.4 | 23.5 | - |
†Note: Composition listed is nominal. Actual composition may vary to meet standard electrical resistance and dimensional tolerances.
Mechanical properties
| Wire size | Yield strength | Tensile strength | Elongation | Hardness |
|---|---|---|---|---|
| Ø | Rp0.2 | Rm | A | |
| mm (in) | MPa (ksi) | MPa (ksi) | % | Hv |
| 1.0 (0.04) | 545 (79) | 760 (110) | 20 | 240 |
| 4.0 (0.16) | 475 (69) | 680 (99) | 18 | 230 |
| Temperature °C | 900 | 1000 | 1100 | 1200 | 1300 |
|---|---|---|---|---|---|
| Temperature °F | 1652 | 1832 | 2012 | 2192 | 2372 |
| MPa | 34 | 18 | 10 | 6 | 4 |
| ksi | 4.9 | 2.6 | 1.5 | 0.9 | 0.6 |
Ultimate tensile strength - deformation rate 6.2 x 10-2/min
| Temperature °C | 800 | 1000 |
|---|---|---|
| Temperature °F | 1472 | 1832 |
| MPa | 1.2 | 0.5 |
| psi | 170 | 73 |
Physical properties
| Density g/cm3 (lb/in3) | 7.10 (0.257) |
|---|---|
| Electrical resistivity at 20°C Ω mm2/m (Ω circ. mil/ft) | 1.45 (872) |
| Poisson's ratio | 0.30 |
| Temperature °C | 20 | 100 | 200 | 400 | 600 | 800 | 1000 |
|---|---|---|---|---|---|---|---|
| Temperature °F | 68 | 212 | 392 | 752 | 1112 | 1472 | 1832 |
| GPa | 220 | 210 | 205 | 190 | 170 | 150 | 130 |
| Msi | 32 | 30 | 30 | 28 | 25 | 22 | 19 |
| Temp. °C | 100 | 200 | 300 | 400 | 500 | 600 | 700 | 800 | 900 | 1000 | 1100 | 1200 | 1300 | 1400 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Temp. °F | 212 | 392 | 572 | 752 | 932 | 1112 | 1292 | 1472 | 1652 | 1832 | 2012 | 2192 | 2372 | 2552 |
| Ct | 1.00 | 1.00 | 1.00 | 1.00 | 1.01 | 1.02 | 1.02 | 1.03 | 1.03 | 1.04 | 1.04 | 1.04 | 1.04 | 1.05 |
| Temperature °C (°F) | Thermal Expansion x 10-6/K (10-6 /°F) |
|---|---|
| 20 - 250 (68-482) | 11 (6.1) |
| 20 - 500 (68-932) | 12 (6.7) |
| 20 - 750 (68-1382) | 14 (7.8) |
| 20 - 1000 (68-1832) | 15 (8.3) |
| Temperature °C | 50 | 600 | 800 | 1000 | 1200 | 1400 |
|---|---|---|---|---|---|---|
| Temperature °F | 122 | 1112 | 1472 | 1832 | 2192 | 2552 |
| W m-1 K-1 | 11 | 20 | 22 | 26 | 27 | 35 |
| Btu h-1ft-1°F-1 | 6.4 | 11.6 | 12.7 | 15.0 | 15.6 | 20.2 |
| Temperature °C | 20 | 200 | 400 | 600 | 800 | 1000 | 1200 | 1400 |
|---|---|---|---|---|---|---|---|---|
| Temperature °F | 68 | 392 | 752 | 1112 | 1472 | 1832 | 2192 | 2552 |
| kJ kg-1 K-1 | 0.46 | 0.56 | 0.63 | 0.75 | 0.71 | 0.72 | 0.74 | 0.80 |
| Btu lb-1 °F-1 | 0.11 | 0.13 | 0.15 | 0.18 | 0.17 | 0.17 | 0.18 | 0.19 |
| Melting point °C (°F) | 1500 (2732) |
|---|---|
| Max continuous operating temperature in air °C (°F) | 1400 (2552) |
| Magnetic properties | The material is magnetic up to approximately 600°C (1112°F) (Curie point). |
| Emissivity - fully oxidized material | 0.70 |