Datasheet

12 Kanthal Appliance Alloys Handbook
2. Physical and Mechanical properties
KANTHAL
APM A-1 A AF AE
Max continuous operating temperature
(element temperature in air), °C 1425 1400 1350 1300 1300
° F 2600 2550 2460 2370 2370
Nominal composition, % Cr 22 22 22 22 22
Al 5.8 5.8 5.3 5.3 5.3
Fe Balance Balance Balance Balance Balance
Ni–––––
Density, g/cm
3
7.10 7.10 7.15 7.15 7.15
Ib/in
3
0.256 0.256 0.258 0.258 0.258
Resistivity at 20 °C, Ω mm
2
m
-1
1.45 1.45 1.39 1.39 1.39
at 68 ° F Ω /cmf 872 872 836 836 836
Temperature factor of the resistivity, C
t
250 °C 480 ° F 1,00 1.00 1.01 1.01 1.01
500 °C 930 ° F 1.01 1.01 1.03 1.03 1.03
800 °C 1470 ° F 1.03 1.03 1.05 1.05 1.05
1000 °C 1830 ° F 1.04 1.04 1.06 1.06 1.06
1200 °C 2190 ° F 1.05 1.04 1.06 1.06 1.06
Coefficient of thermal expansion, K
-1
20-100 °C 68-210 ° F –––––
20-250 °C 68-480 ° F 11·10
-6
11·10
-6
11·10
-6
11·10
-6
11·10
-6
20-500 °C 68-930 ° F 12·10
-6
12·10
-6
12·10
-6
12·10
-6
12·10
-6
20-750 °C 68-1380 ° F 14·10
-6
14·10
-6
14·10
-6
14·10
-6
14·10
-6
20-1000 °C 68-1840 ° F 15·10
-6
15·10
-6
15·10
-6
15·10
-6
15·10
-6
Thermal conductivity at 50 °CW m
-1
K
-1
11 11 11 11 11
at 122 ° F Btu in ft
-2
h
-1
° F
-1
76 76 76 76 76
Specific heat capacity, kJ kg
-1
K
-1
, 20 °C 0.46 0.46 0.46 0.46 0.46
Btu lb
-1
° F
-1
, 68 ° F 0.110 0.110 0.110 0.110 0.110
Melting point (approx.), °C 1500 1500 1500 1500 1500
° F 2730 2730 2730 2730 2730
Mechanical properties* (approx.)
Tensile strength, N mm
-2
680 680 725 700 720
psi 98600** 110200 105200 101500 104400
Yield point, N mm
-2
470 545 550 500 520
psi 68200** 79000 79800 72500 74500
Hardness, Hv 230 240 230 230 230
Elongation at rupture, % 20** 20 22 23 20
Tensile strength at 900 °C, N mm
-2
40 34 34 37 34
at 1650 ° F, psi 5800 4900 4900 5400 4900
Creep strength ***
at 800 °C, N mm
-2
8.2 1.2 1.2 – 1.2
at 1470 ° F, psi 1190 70 70 – 170
at 1000 °C, N mm
-2
– 0.5 0.5 – –
at 1830 ° F, psi – 70 70 – –
at 1100 °C, N mm
-2
–––0.7–
at 2010 ° F, psi – – – 100 –
at 1200 °C, N mm
-2
–––0.3–
at 2190 ° F, psi–––40–
Magnetic properties
1
)
1
)
1
)
1
)
1
)
Emissivity, fully oxidized condition 0.70 0.70 0.70 0.70 0.70
* The values given apply for sizes of approx. 1.0 mm diameter 0.04 in .
** 4.0 mm
0.16 in . Thinner gauges have higher strength and hardness values while the corresponding values are lower for
thicker gauge.
*** Calculated from observed elongation in a Kanthal standard furnace test. 1 % elongation after 1000 hours.