Alkrothal® 720

Resistance heating wire and resistance wireDatasheet

Datasheet updated 2024-09-05 11:06 (supersedes all previous editions)

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 materials under the trademark Kanthal^®.

Alkrothal^® 720 wire is a ferritic iron-chromium-aluminium alloy (FeCrAl alloy) for use at temperatures up to 1000°C (1830°F).

Typical applications for Alkrothal^® 720 are braking resistors, rheostats, etc. It is also used as electrical heating elements in industrial applications.

Chemical composition

	C %	Si %	Mn %	Cr %	Al %	Fe %
Nominal composition					4.0	Bal.
Min	-	-	-	12.0	-
Max	0.08	0.7	0.7	14.0	-

Mechanical properties

Thickness	Yield strength	Tensile strength	Elongation	Hardness
	R_p0.2	R_m	A
mm	MPa	MPa	%	Hv
1.0-3.0	420	550	20	200

Poisson's ratio 0.30
Mechanical properties at elevated temperature
Ultimate tensile strength - deformation rate 6.2 x 10 -2 min -1

Temperature °C	900
MPa	30

Creep strength - 1% elongation in 1000 h
Temperature °C	800	1000
MPa	4	1

Physical properties

Density g/cm³	7.30
Electrical resistivity at 20°C Ω mm²/m	1.20
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
Ct	1.00	1.02	1.03	1.04	1.05	1.08	1.09	1.10	1.11	1.11	1.12

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	20
W m^-1 K^-1	16

Specific heat capacity
Temperature °C	20	200	400	600	800	1000
kJ kg^-1 K^-1	0.46	0.63	0.72	1.00	0.80	0.73

Melting point °C	1500
Max continuous operating temperature in air °C	1000
Magnetic properties	The material is magnetic up to approximately 600°C (Curie point).
Emissivity - fully oxidized material	0.70