Nikrothal® 40

Resistance heating wire and resistance wireDatasheet

Datasheet updated 2024-09-05 11:08 (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^®.

Nikrothal^® 40 wire is an austenitic nickel-chromium alloy (NiCr alloy) for use at temperatures up to 1100°C (2010°F). The alloy is characterized by high resistivity and good oxidation resistance. It has good ductility after use and excellent weldability.

Typical applications for Nikrothal^® 40 are night-storage heaters, convection heaters, heavy duty rheostats and fan heaters. The alloy is also used for heating cables and rope heaters in defrosting and de-icing elements, electric blankets and pads, car seats, baseboard heaters and floor heaters, resistors.

Chemical composition

	C %	Si %	Mn %	Cr %	Ni %	Fe %
Nominal composition						Bal.
Min	-	1.6	-	18.0	34.0
Max	0.10	2.5	1.0	21.0	37.0

Mechanical properties

Wire size	Yield strength	Tensile strength	Elongation	Hardness
Ø	R_p0.2	R_m	A
mm	MPa	MPa	%	Hv
1.0	340	675	35	180
4.0	300	650	30	160

Mechanical properties at elevated temperature
Temperature °C	800	900	1000
MPa	170	95	58

Ultimate tensile strength - deformation rate 5.0 x 10^-2/min

Creep strength - 1% elongation in 1000 h
Temperature °C	800	1000
MPa	20	4

Physical properties

Density g/cm³	7.90
Electrical resistivity at 20°C Ω mm²/m	1.04

Temperature factor of resistivity
Temperature °C	100	200	300	400	500	600	700	800	900	1000	1100
Ct	1.03	1.06	1.10	1.12	1.15	1.17	1.19	1.21	1.22	1.23	1.24

Coefficient of thermal expansion
Temperature °C	Thermal Expansion x 10^-6/K
20 - 250	16
20 - 500	17
20 - 750	18
20 - 1000	19

Thermal conductivity
Temperature °C	20	100	200	300	400	500	600	700	800	900	1000	1100
W m^-1 K^-1	13	14	15	16	18	19	21	22	24	25	26	28

Specific heat capacity
Temperature °C	20	100	200	300	400	500	600	700	800	900	1000	1100
kJ kg^-1 K^-1	0.50	0.50	0.50	0.51	0.54	0.57	0.60	0.62	0.64	0.67	0.70	0.73

Melting point °C	1390
Max continuous operating temperature in air °C	1100
Magnetic properties	The material is non-magnetic
Emissivity - fully oxidized material	0.88