01
N6 ≠ N4 above 315 °C
Both are “pure nickel”. The difference is carbon — 0.15 % against 0.02 % — and above roughly 315 °C that difference is the difference between a part that survives and one that embrittles.
Tool 01 · Selection
Grade cross-reference
A drawing written in GB, a purchase order written in UNS, a datasheet written in W.Nr. — this table puts them in the same row, with the resistivity and service limit that usually decide the substitution.
| Grade | GB / China | UNS | W.Nr. | JIS | ρ, µΩ·m | TCR, ppm/K | Max service, °C | Family |
|---|---|---|---|---|---|---|---|---|
| Nickel 200 | N6 | N02200 | 2.4060 / 2.4066 | NW2200 | ≈ 0.069 | ≈ 5 700 | 315 | Pure nickel |
| Nickel 201 | N4 | N02201 | 2.4061 / 2.4068 | NW2201 | ≈ 0.069 | ≈ 5 700 | 600 | Pure nickel |
| Monel 400 | Ni70Cu28 | N04400 | 2.4360 | NW4400 | ≈ 0.51 | ≈ 1 900 | 480 | Monel |
| Constantan | 6J40 | — | 2.0842 (CuNi44 family) | CNC1 | ≈ 0.49 | ± 20 | 400 | Constantan |
| Manganin 6J8 | 6J8 | — | 2.1362 family | — | 0.42 – 0.47 | ± 20 | 60 – 100 | Manganin |
| Manganin 6J12 | 6J12 | — | 2.1362 | — | ≈ 0.47 | ± 10 – 20 | 60 – 100 | Manganin |
| Manganin 6J13 | 6J13 | — | 2.1362 family | — | 0.43 – 0.44 | ± 20 | 60 – 100 | Manganin |
| CuNi44 | NC050 | — | 2.0842 | CNC1 | ≈ 0.49 | ± 40 | 400 | Copper-nickel |
| CuNi23 | NC025 | — | 2.0888 (CuNi25) | — | ≈ 0.30 | ± 40 | 400 | Copper-nickel |
| Type K, positive (KP) | NiCr10 | — | — | — | ≈ 0.706 | ≈ 100 – 150 | 1200 | Thermocouple |
| Type K, negative (KN) | NiSi (Ni95Mn2Al2Si1) | — | — | — | ≈ 0.29 | ≈ 600 – 800 | 1200 | Thermocouple |
| Type E / J / T, negative | Constantan / Cu55Ni45 | — | 2.0842 | CNC1 | ≈ 0.49 | ± 20 | 400 | Thermocouple |
| Type J, positive (JP) | Iron | — | 1.0345 | — | ≈ 0.12 | ≈ 6 000 | 750 | Thermocouple |
| Type T, positive (TP) | Copper | C11000 | 2.0090 | — | ≈ 0.017 | ≈ 4 000 | 400 | Thermocouple |
No grade matches that search.
Indicative equivalence for selection only. Designations differ in detail between systems — confirm against the standard your drawing cites, and our quotation states the designation we will produce to.
Three substitutions that go wrong
Where the cross-reference is not enough
02
6J40 vs CuNi44
Nearly the same alloy, two different contracts. Constantan is controlled for EMF against copper; CuNi44 is controlled as a resistance alloy. Use the wrong one and the drift shows up months later.
03
Manganin is not a heating alloy
Its service limit of 60–100 °C is set by the temperature coefficient degrading, not by melting. It is a measurement material; specifying it hot throws away the property you bought.
Not sure which row your drawing maps to?
Send the designation on the drawing and the application. We will tell you what we would produce — and say so plainly if the grade is outside our range.
Send a specification Resistance calculator