Nikrothal® 70

Resistance heating wire and resistance wireDatasheet

Datasheet updated 2024-09-05 11:09 (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^® 70 wire is an austenitic nickel-chromium alloy (NiCr alloy) for use at temperatures up to 1250°C (2280°F). The alloy is characterized by high resistivity and good oxidation resistance. It has good ductility after use and excellent weldability.

Nikrothal^® 70 is particularly well suited for reducing atmospheres, as it is not subject to 'green rot'.

Nikrothal^® 70 is used in electrical heating elements in industrial furnaces. The alloy is particularly well suited for reducing atmospheres, as it is not subject to 'green rot'.

Chemical composition

	C %	Si %	Mn %	Cr %	Fe %	Ni %	Trace elements
Nominal composition						Bal.	Added
Min	-	0.5	-	29.0	-	-
Max	0.15	2.0	1.0	32.0	5.0	-

Mechanical properties

Wire size	Yield strength	Tensile strength	Elongation	Hardness
Ø	R_p0.2	R_m	A
mm	MPa	MPa	%	Hv
1.0	430	820	30	185
4.0	425	800	30	185

Physical properties

Density g/cm³	8.10
Electrical resistivity at 20°C Ω mm²/m	1.18

Temperature factor of resistivity
Temperature °C	100	200	300	400	500	600	700	800	900	1000	1100	1200
Ct	1.01	1.02	1.03	1.04	1.05	1.05	1.04	1.04	1.04	1.05	1.05	1.06

Coefficient of thermal expansion
Temperature °C	Thermal Expansion x 10^-6/K
20 - 250	13.7
20 - 500	14.6
20 - 750	15.8
20 - 1000	17.1

Thermal conductivity
Temperature °C	20	100	200	300	400	500	600	700	800	900	1000	1100
W m^-1 K^-1	13	13	14	15	17	19	20	22	24	26	28	29

Specific heat capacity
Temperature °C	20	100	200	300	400	500	600	700	800	900	1000	1100
kJ kg^-1 K^-1	0.46	0.46	0.48	0.50	0.53	0.55	0.58	0.60	0.63	0.65	0.67	0.71

Melting point °C	1380
Max continuous operating temperature in air °C	1250
Magnetic properties	The material is non-magnetic
Emissivity - fully oxidized material	0.88