What Is High Temperature Wire?

High temperature wires are for applications where temperatures exceed 150 degrees Celsius in normal use. Applications for heat-resistant wire include internal wiring of furnaces, cooking appliances, and industrial heating applications. Common insulation and jacket materials used for high temperature lead wires include silicone, perfluoroalkoxy (PFA), polytetrafluoroethylene (PTFE), mica, and fiberglass.

Factors to Consider When Selecting Heat-resistant Wire

The most important characteristic of high temp wire is the ability to withstand the maximum operating temperature at the point of application. Secondly, consider the wire's ampacity, (maximum current rating) at that temperature. Note that for a given American Wire Gauge (AWG) size, the ampacity of high temperature cable is higher than for standard electrical wires because of the higher allowable operating temperature. Other points to consider include flexibility, abrasion, and chemical resistance.

Conductor Materials

Pure copper corrodes more easily at high temperatures, so high temperature wire uses the following heat-resistant conductor materials:

  • Tin-plated copper: Suitable for moderately high temperatures up to 180ºC
  • Nickel-plated copper: For high temperatures up to 450ºC
  • Nickel wire: Able to withstand very high temperatures above 450ºC

Common Types of High Temperature Wire

Silicone Insulated Wires (180ºC)

You can use silicone insulated single conductors for operating temperatures up to 180ºC. Silicone can withstand 250ºC for a short time and it has good low-temperature properties down to -25ºC. This material is self-extinguishing and has good flame-retardant properties. The addition of a fiberglass jacket impregnated with a high temperature saturant improves abrasion resistance and heat resistance. Examples include silicone rubber cable, silicone rubber motor lead (SRML), and silicone fixture (SF-2) wire.

Our PVC Single Pair Thermocouple Wire and PVC Multi-Pair Thermocouple Wire are offered in numerous styles and configurations for situations where PVC insulation may be beneficial. Other thermocouple wire types include FEP, TFE, PFA, Fiberglass, and CERAMAFLEX thermocouple wire.

You may see thermocouple wire listed as a thermocouple grade wire or extension grade wire. Thermocouple grade wire is used to make the sensing point of the thermocouple. Extension grade wire is used to extend a thermocouple signal from a probe back to the instrument reading the signal. Both types of thermocouple wire are designed and constructed for continued, dependable, long term use.

Although thermocouple wire is a commonly used high-temp cable, additional high-temperature cable types are popular for various applications. SRML, SF-2/SEW, TGGT, MGT, and FLAME 1000 Power Cable are all styles of high-temperature wire used on a regular basis. SRML high-temperature wire is a motor lead wire for hazardous locations and may be used for internal wiring of equipment in high-temperature environments. SF-2/SEW high-temperature wire has a variety of applications that include internal wiring of appliances, internal wiring of electric clothes dryers, or motor lead wire for hazardous locations. High temp wire, TGGT, may be used for the internal wiring of commercial, industrial, and household ovens, cooking and drying equipment, and more.

For more information on high-temperature wire, check out our product FAQ page.