Chromel Alumel thermocouple material for broad industrial temperature measurement

Type K is the most commonly specified base-metal thermocouple type. It uses Chromel as the positive leg and Alumel as the negative leg, giving a broad useful range and strong fit for general industrial, heat-treat, turbine support, validation, and OEM temperature measurement.

Thermometrics manufactures Type K thermocouple assemblies as MI cable probes, wire sensors, plug-and-lead sensors, head-style assemblies, surface sensors, tube-skin thermocouples, rake assemblies, and custom replacement parts built to drawing.

Common Type K RFQ details

  • Temperature range and atmosphere
  • Grounded, ungrounded, or exposed junction
  • Sheath alloy and diameter
  • Insertion length, lead length, and termination
  • Standard or special limits of error

Type K temperature range

Type K is commonly referenced for approximately -328°F to 2282°F (-200°C to 1250°C), but the practical assembly rating depends on sheath material, wire insulation, environment, probe diameter, junction style, and service life expectations.

Grounded vs ungrounded Type K

Grounded junctions respond quickly because the measuring junction is connected to the sheath. Ungrounded junctions are insulated from the sheath and are often selected for electrical isolation, noisy environments, or multi-channel systems.

Type K chart PDFs

Celsius Chart

Download the Type K thermocouple reference table in Celsius.

Open C chart

Fahrenheit Chart

Download the Type K thermocouple reference table in Fahrenheit.

Open F chart

Color Codes

Review common thermocouple wire color code references.

View color codes

Thermocouple Family

Compare Type K with J, T, E, N, R, S, and B options.

View thermocouples

When Type K is a strong fit

  • General industrial high-temperature measurement
  • MI cable probes where vibration and routing matter
  • Heat-treat, furnace support, turbine support, and OEM equipment
  • Replacement probes where the existing system expects Type K input

When to review alternatives

Type N may be reviewed where oxidation stability at elevated temperature is important. Noble-metal Type R, S, or B may be reviewed for very high-temperature furnace service. Type T or E may be reviewed for lower-temperature or cryogenic work.

Need a Type K thermocouple built to fit?

Send the drawing, temperature range, sheath, junction, lead, connector, and documentation requirements.