Grade datasheet · Type K
Type K Thermocouple Wire
The most widely used base-metal thermocouple. Positive leg NiCr (KP), negative leg NiSi (KN). We draw both legs from the same melt and ship them together, so nobody has to pair spools from two batches before a probe can be built.
0.018–6.00Diameter, mm
1 kgMinimum order
3–7 dLead time
MTCWith every lot
Identification
What this grade is called elsewhere
| System | Designation |
|---|---|
| IEC | Type K (IEC 60584-1) |
| Positive leg | NiCr10 / KP / NiCr20AlSi designation family |
| Negative leg | NiSi / KN / Ni95Mn2Al2Si1 |
| ASTM | E230 (EMF tables) |
| GB | K 型热电偶丝 |
Grade equivalence is indicative. Confirm against the standard your drawing cites; our quotation states the designation we will produce to.
Composition
Nominal chemistry, % by weight
| Element | Nominal / limit |
|---|---|
| KP — Ni | Balance |
| KP — Cr | ≈ 10 |
| KN — Ni | Balance |
| KN — Mn | ≈ 2 |
| KN — Al | ≈ 2 |
| KN — Si | ≈ 1 |
Properties
What the numbers are, and where they stop
| Property | Value |
|---|---|
| Resistivity, KP | ≈ 0.706 µΩ·m |
| Resistivity, KN | ≈ 0.29 µΩ·m |
| EMF at 500 °C | ≈ 20.64 mV |
| EMF at 1000 °C | ≈ 41.28 mV |
| Max service, bare wire | ≈ 1200 °C (oxidising) |
| Tolerance class | Class 1 or Class 2 on request |
Nominal values for selection only. Contractual composition, tolerance and mechanical properties are stated on the inspection report issued with each shipment.
Use
Where this grade earns its place
- Thermocouple probes and assemblies
- Mineral-insulated (MI) cable conductors
- Furnace and kiln temperature control
- Compensating and extension leads
Family: Thermocouple Wire
Questions we get asked
Do you supply positive and negative legs as a pair?
Yes. Both legs are drawn from the same melt and shipped together, which removes the pairing step on your bench. This is the reason most probe makers come to us for small and mid-size lots.
What is the finest diameter?
0.018 mm in routine production, with the measured resistance per metre recorded on the spool label.
Class 1 or Class 2?
Both, to IEC 60584-1. Class 1 roughly halves the permitted deviation of Class 2 and is worth specifying where the loop is used for control rather than indication.
Send the specification — diameter, grade, temper, quantity.
We come back with a confirmed lead time and the documentation we can issue for the shipment. 100 g sample at cost; orders from 1 kg.
Request a quotation Order a 100 g sample