Type C and Type D, thermocouple wire made from Tungsten Rhenium Alloy

Type C and Type D thermocouple wires have been developed to facilitate ultra-high temperature measurement in vacuum, reducing or inert atmospheres.

These thermocouple wires are both Tungsten Rhenium alloys and can be used for guaranteed temperature measurement up to 2871°C.

Are you in need of a complete sensor rather than just wire?

Visit our high-temperature thermocouple page. On this page, complete assemblies are explained, and through our brochure, you can directly configure one.

In short about type C and D wire;

  • standard available in diameters ranging from 0.076 mm to 1.0 mm
  • provided in ASTM E 230 Standard limits
  • supplied with a calibration certificate
  • produced in USA with USA sourced materials
  • can be used when extreme high temperatures need to be measured
  • should not be used in oxygen, nitrogen or hydrogen atmospheres

Our standard Type C and D wire items

Thermocouple wire typeClassOutside Diameter in mmDelivery time
Type C wire
Type D wire
ASTM E 230 Standard limits0.076 mm1 weekSend inquiry
Type C wire
Type D wire
ASTM E 230 Standard limits0.127 mm1 weekSend inquiry
Type C wire
Type D wire
ASTM E 230 Standard limits0.198 mm1 weekSend inquiry
Type C wire
Type D wire
ASTM E 230 Standard limits0.254 mm1 weekSend inquiry
Type C wire
Type D wire
ASTM E 230 Standard limits0.381 mm1 weekSend inquiry
Type C wire
Type D wire
ASTM E 230 Standard limits0.30 mm1 weekSend inquiry
Type C wire
Type D wire
ASTM E 230 Standard limits0.50 mm1 weekSend inquiry
Type C wire
Type D wire
ASTM E 230 Standard limits1.00 mm1 weekSend inquiry
Delivery times stated are workingsdays with delivery to Kamet’s warehouse

Please contact us if you need different diameters. We can supply more custom made diameters (combinations) than stated above.

What are the differences between thermocouples Type C and Type D?

These two thermocouples are very similar in composition, ductility and performance. The only slight differences are that the average EMF of Type D is marginally higher than that of Type C. Furthermore, Type C is the only ASTM approved tungsten thermocouple while “Type D” is in fact an industry term and not an official standard thermocouple letter designation.

Type C (W5Re/W26Re) thermocouples are by far the most commonly used. However, there are some applications where Type D is specifically requested by customers.

Industrial uses of Tungsten Rhenium Alloys

Tungsten thermocouples are the ideal choice for high temperature vacuums as well as either hydrogen or other inert gas environments. They are specifically selected for temperatures and conditions beyond the capabilities of platinum. Avoid usage of Type C and Type D thermocouple wires are in the presence elevated temperatures in oxygen, nitrogen or hydrogen due to embrittlement

Vacuum furnaces at extreme temperatures are one of the most common applications of these thermocouples. Others include:

  • Aerospace
  • (Solar) Power generation
  • Semiconductor processing and equipment
  • (Medical) Research
  • Military

Kamet’s Tungsten Rhenium thermocouple wire products

Kamet offers a variety of high quality Type C and Type D thermocouple with two to four week delivery time. Our products offer the following advantages:

  • Calibration up to 2315°C through actual testing and not extrapolation
  • Full traceability and certification to NIST standards
  • Certifications are user-friendly, with deviations indicated in mV, °F, or °C
  • Wire sizes 0.0127 to 1 mm diameter and larger diameters are available.
  • Type C and Type D wires are supplied at both standard and customized lengths with no upper limit.
  • The thermocouple wires are doped which ensures superior ductility in comparison to un-doped materials.
  • Extra services are available such as;
    – Customized EMF tolerances and sizes for critical applications
    – The recording of calibration data from both ends of long-length spools (end to end) instead of an average.

Depending on the demands (environment and temperature) of the application, these thermocouples can be used bare, with ceramic insulators or in mineral insulated (MI) cable with a metal sheath. To ensure accuracy and durability it is essential to make a thorough assessment of the application so that the correct configuration of insulators, wires and atmosphere is achieved. The in-house experts at Kamet are able to support and advise you in this process.

Read here more about the rather difficult manufacturing process for type C thermocouples wires

Physical Properties of Tungsten Rhenium Alloys

Read here the mechanical and physical properties of the Tungsten Rhenium Alloy.

Kamet and Concept Alloys

Based in the United States and founded in 2002, Concept Alloys is our partner for Tungsten Rhenium thermocouple wire. Concept Alloys are widely known for their proprietary testing and calibration methodologies used to routinely calibrate each end of every coil produced. This expertise and commitment to quality is further reflected in the fact that every finished coil has to meet their own end-to-end uniformity tolerance every 100°C, from +100°C to +2300°C. They have extensive experience in Tungsten Rhenium alloys and have built up unparalleled knowledge to provide great technical support. Furthermore, the company works with New Product Development teams in order to further knowledge on temperature measurement, and oxidation and corrosion resistance for Tungsten Rhenium alloys.

This commitment to quality, the focus on in-house expertise and innovative approach matches the business ethic of Kamet perfectly.

Kamet furthermore offers her customers:

  • Excellent customer service via phone or mail. Our multilingual team will ensure you receive a response within 24 hours.
  • Kamet provides 24 hour access to a large range of products via our customer portal as well as extensive product information on the customer portal.
  • Our expert technical sales engineers are available to work with you in finding the best (custom) product for your situation.

Get an quote!

Do you have any further questions? Please let us know and our specialists will be happy to advise you.


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