OMEGA Thermocouple Wire / Extension Wire (Full Range) | K, J, T, E, N duplex wire and KX, JX, TX, EX, RX / SX extension wire, insulation from ceramic fiber to PVC, ANSI color code

OMEGA Thermocouple Wire / Extension Wire (Full Range): Multiple Insulation Materials

Overview

OMEGA (now DwyerOmega) thermocouple wire comes in two classes: thermocouple grade, used to make the sensing junction, and extension grade, used to extend the thermocouple signal to an instrument or controller. Duplex insulated thermocouple-grade wire is available in types K, J, T, E and N; extension wire in KX, JX, TX, EX, RX / SX (copper / alloy 11) and BX (copper / copper). Insulation ranges from high-temperature ceramic fiber (Nextel), silica and fiberglass to PFA, Kapton, TFE, FEP and PVC; the maximum service temperature depends on the insulation and the wire gauge, whichever is lower. Thermocouple-grade wire is available with special limits of error (SLE); wire uses the ANSI color code as standard, and the IEC color code must be ordered separately. Type R, S and B noble-metal (platinum-rhodium) bare wire and tungsten-rhenium bare wire are also available. Please tell us the type, insulation, gauge and length for a quotation.

Key Specifications

• Thermocouple-grade insulation temperature rating (type K, by gauge): Ceramic fiber XC / silica XS: 14 AWG 1090 ℃, 20 AWG 980 ℃, 24 AWG 870 ℃; Refrasil XR 870 ℃; high-temperature fiberglass HH 704 ℃; fiberglass braid GG 482 ℃; Kapton KK, PFA TT, PFA with fiberglass TG, TFE tape 260 ℃; FEP FF 200 ℃; PVC 105 ℃
• Extension wire insulation temperature rating: Fiberglass EXGG, PFA EXTT, FEP EXFF: 200 ℃; PVC EXPP: 105 ℃ (whichever of the wire and insulation is lower); type B extension wire (copper / copper) 100 ℃
• Types: Thermocouple grade: K, J, T, E, N; extension grade: KX, JX, TX, EX, RX / SX, BX, CX
• Noble-metal bare wire: Types R and S for continuous use up to 1398 ℃ in oxidizing or inert atmospheres, 1482 ℃ short term; type B continuous use up to 1704 ℃; diameter 0.025–0.812 mm
• Wire construction: Solid or stranded; 14–40 AWG (depending on model); stainless steel overbraid or twisted shielded options
• Color code and tolerance: ANSI MC96.1 color code (IEC 584-3 color code to order); standard tolerance or special limits of error SLE (add -SLE to the model number)

Applications

• Making and wiring thermocouples for heat-treatment furnaces, drying equipment and test chambers.
• Extension wiring between sensors and controllers or recorders.

Specifications per the OMEGA XC-K-TC-WIRE, EXGG-KX-WIRE and SPPL specification sheets and ANSI / IEC color code charts (dwyeromega.com, formerly omega.com, retrieved 2026-10-24); temperature ratings for types other than K follow each model's specification sheet.