⚫ Type J Thermocouple Wire

Type J (Iron / Constantan) thermocouple wire offers dependable temperature measurement for general-purpose and industrial applications. Designed for stable performance up to approximately 1400°F (760°C), it provides strong output and consistent accuracy. TIP TEMPerature Products supplies Type J thermocouple wire in various gauges, insulation materials, and spool lengths to support precise installations and long-term reliability.

Need help selecting a Product?

Use the Filters on the Left-Hand margin to narrow your search!

Call our Thermal Advisors @ 1-800-TIP-TEMP with any questions or submit our online Contact Us form!

Type J Thermocouple (Iron+ / Constantan –) J was a commonly used thermocouple wire. It’s remains popular with installations that already have existing "J" thermocouples installed. It's accuracy is comparable to type "K", and has a wide temperature range. Type J wire is commonly found in Industrial applications. Be careful of the IRON leg because its alloy will rust if exposed to moisture. Some of our clients use gold plated thermocouple connectors if "J" wire is used outdoors. Maximum continuous temperature is around 750°C / 1,400°F depending on wire gauge size.

Note: RED is always Negative "–" in the thermocouple world!

Thermocouple GRADE Wire is recommended for measuring process temperature. J Thermocouple Grade wire always has a BROWN jacket ( Teflon or Fiberglass ) with White and Red conductors. This wire is available in standard limits ±2°C or Special Limits ±1°C. Most wire in this section is Standard. Please contact a Thermal Advisor to request Special Limits

Thermocouple EXTENSION Wire is used to connect Thermocouples to Instrumentation. It's accuracy is guaranteed over a limited temperature range. ( -40 ~ 221°F / -40 ~ 105°C ) Type J Extension Grade Wire always has a BLACK PVC jacket with White + and Red –conductors