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Datasheet · Type J · Rev. 08

Type J Stranded Wire
Iron / Constantan

Multi-strand twisted wire for flexibility and vibration resistance. 7/19/37 strand configurations available.

Type J Stranded Wire: φ0.1mm – φ5.0mm, −40°C to +750°C, IEC 60584-1 Class 1
Ø range
φ0.1mm – φ5.0mm
Temp
−40°C to +750°C
EMF tol.
±1.5°C (0–275°C) / ±0.4% (275–750°C)
Testing
100%

Technical Specifications

Type J Stranded Wire — Iron / Constantan at −40°C to +750°C, multi-strand (7 / 19 / 37) from φ0.1mm – φ5.0mm, supplied to IEC 60584-1 Class 1.

Property Specification
Positive Leg Iron (Fe 99.5%)
Negative Leg Constantan (CuNi 55/45)
Temperature Range −40°C to +750°C
Diameter Range φ0.1mm – φ5.0mm
Diameter Tolerance ±0.005mm (fine) / ±0.02mm (standard)
EMF Tolerance ±1.5°C (0–275°C) / ±0.4% (275–750°C)
Standards IEC 60584-1 Class 1 / ASTM E230 / DIN EN 60584
Surface Finish Bright / Oxidized / Electro-polished
Condition Hard (cold-drawn) / Soft (annealed) / Bright finished
Packaging DIN 125 spool / Coil / Custom reel
Coil Weight 5kg / 10kg / 20kg standard
Testing & Traceability 100% eddy-current + resistance + dimensional · MTC · EMF calibration certificate · Furnace batch traceability

How to specify Type J Stranded Wire

  1. Confirm the alloy for your operating temperature — Iron / Constantan, rated −40°C to +750°C in air.
  2. Pick the conductor diameter from φ0.1mm – φ5.0mm (diameter tolerance ±0.005mm (fine) / ±0.02mm (standard)) — supplied as 7, 19 or 37 strand Iron / Constantan construction for −40°C to +750°C.
  3. Choose the temper condition for this J · Iron / Constantan wire — Hard (cold-drawn) / Soft (annealed) / Bright finished. Soft or annealed tempers are usual where multi-strand J wire is routed around moving parts.
  4. Choose the surface finish for J · Iron / Constantan — Bright / Oxidized / Electro-polished. Finish is selected for the service environment along the flexing run.
  5. Choose the packaging — DIN 125 spool / Coil / Custom reel, standard coil weights 5kg / 10kg / 20kg standard. Spooled so the J multi-strand pays out without twisting.
  6. Quote Type J Stranded Wire against IEC 60584-1 Class 1 and request the MTC / EMF calibration certificate with the batch number for traceability.

Which thermocouple type fits the job

These are the J-type ranges as quoted for solid wire; the same Iron / Constantan alloys are available in the multi-strand form described on this page. Confirm the type first, then choose the strand configuration.

Type Alloy Range EMF tolerance
E Chromel / Constantan −200 … +900 °C ±1.5°C (0–275°C) / ±0.4% (275–900°C)
J this page Iron / Constantan −40 … +750 °C ±1.5°C (0–275°C) / ±0.4% (275–750°C)
K Chromel / Alumel −200 … +1370 °C ±1.5°C (0–375°C) / ±0.4% (375–1000°C)

See the full 5-type comparison →

Verification & quality evidence

  • IEC 60584-1 Class 1 / ASTM E230 / DIN EN 60584
  • 100% eddy-current + resistance + dimensional · MTC · EMF calibration certificate · Furnace batch traceability
  • Third-party testimonials and site references are being collected for this product line — ask for Type J Stranded Wire reference contacts in comparable flexing or vibrating installations when you request a quote.

Frequently Asked Questions

What alloy is Type J stranded wire made from?

Iron (Fe 99.5%) for the positive leg and Constantan (CuNi 55/45) for the negative leg.

What temperature range and diameters does Type J stranded wire cover?

−40 °C to +750 °C, in diameters from φ0.1 mm to φ5.0 mm.

Where is Type J stranded wire used?

Extruder and moulding equipment, food processing and HVAC plant, where the cable is routed around moving parts and the conductors must flex without work-hardening.

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Bottom line: Type J Stranded Wire (Iron / Constantan) covers −40°C to +750°C across φ0.1mm – φ5.0mm, with EMF tolerance ±1.5°C (0–275°C) / ±0.4% (275–750°C). Supplied to IEC 60584-1 Class 1 with 100% EMF testing, MTC and furnace batch traceability.

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