Grade reference: 15 electric heating and resistance alloys

Composition windows, resistivity, maximum service temperature and typical applications. All values are typical; confirm against the mill certificate for your batch.

FeCrAl heating alloys

Grade	Cr %	Al %	ρ20 μΩ·m	Max temp. °C	Typical use
0Cr25Al5	20.0–23.0	4.5–6.5	1.40	1,300	General high-temperature furnaces, continuous operation
0Cr21Al6Nb	20.0–23.0	5.0–7.0	1.42–1.45	1,350	Better high-temperature strength, long spans
0Cr27Al7Mo2	26.0–28.0	6.0–7.5	1.53	1,400	Ultra-high temperature, large element spans
1Cr13Al4	12.0–15.0	3.5–4.5	1.25	1,000	Low-temperature, cost-sensitive applications
0Cr23Al5	22.0–24.0	4.5–5.5	1.35	1,250	Intermediate between 1Cr13Al4 and 0Cr25Al5

Ni-Cr and Ni-Cr-Fe

Grade	Ni %	Cr %	ρ20 μΩ·m	Max temp. °C	Typical use
Cr20Ni80	75.0–78.0	20.0–23.0	1.09	1,200	Frequent cycling, vibration, welding
Cr15Ni60	55.0–58.0	15.0–18.0	1.12	1,100	Medium temperature, cost-performance balance
Cr30Ni70	68.0–72.0	28.0–31.0	1.18	1,250	High nickel, corrosion resistance
Cr20Ni35	34.0–37.0	18.0–21.0	1.04	1,100	Ni-Cr-Fe, good oxidation resistance

Pure nickel and copper-nickel

Grade	Ni %	ρ20 μΩ·m	Max temp. °C	Typical use
Ni200	≥99.6	0.096	600	Low-voltage heating, battery tabs, corrosion resistance
N4 / N6	≥99.5	0.096	600	Same as Ni200, Chinese designations
6J40 (Constantan)	39.0–41.0	0.48	400	Precision resistors, shunts, thermocouples
Manganin	2.0–3.0 Mn, 11.0–13.0 Mn	0.44–0.48	300	Standard resistors, low thermal EMF

Precision resistance alloys

Grade	Composition	ρ20 μΩ·m	TCR ppm/°C	Typical use
6J12	Cu-Mn	0.43–0.47	±20	Precision resistors
6J20	Ni-Cr	1.08–1.12	±10	Precision resistors, strain gauges
6J40	Cu-Ni (Constantan)	0.48	±20	Shunts, thermocouple negative leg

Selection notes

Pick by three numbers: service temperature, atmosphere and cycling frequency.

Temperature. Use the element temperature, not the furnace temperature — the element runs 50–150 °C hotter than the furnace.
Atmosphere. FeCrAl is the better choice in air; Ni-Cr is more forgiving in reducing or carbon-bearing atmospheres.
Cycling. Frequent start-stop favours Ni-Cr because of its toughness. Continuous operation favours FeCrAl on cost.

Need a recommendation?

Send the furnace type, service temperature, atmosphere and element span. We will reply with a grade and the surface-load figure to work to.