Expansion Wax - Expands 15 percent when melted


This wax expands by about 15 percent when melted, then contracts as it cools down and solidifies. The wax can be tailored to melt within a narrow temperature range, and it can withstand thousands of expansion cycles without suffering critical property degradation.

Used for:
Expansion wax is used as the driving element in thermal wax actuators, which exert a mechanical force as the temperature rises. The principal application is in thermostats used in automotive engine cooling systems. The wax actuators are also used for safety valves for heated water tanks.

The wax is available with activation temperatures between 17°C and 104°C, but the company producing the wax can also tailor the melting point and expansion characteristics to specific applications. 

The sample:
The sample we have is fully melted and expanded at 87°C. You can get:

  • A few grams, which can be used to get a feel for the material
  • 50 grams for experiments
All samples come with a laminated information card.



    Ask a Question
    • Would you have a wax suitable for opening vents on a greenhouse?

      We only supply the sample you see on this website. The manufacturer supplies different variants including a low-temperature variant that expands between ~18°C and ~24°C. The sample we sell has an attached information card which includes contact information for the manufacturer.

    • I wish to know where I can buy the same wax which you used in your experiment described above.

      The sample comes with an information card that includes contact details for the manufacturer. 

    • I'm looking for expansion wax with activation temperatures between 30 and 40 degrees. Can you provide also samples with melting point at about 32 degrees, about 35 degrees and about 37 degrees? If so, can you please specify the cost and how to order these samples. Thanking you in advance,

      We only have the sample listed. Please send us an email and we'll connect you with the supplier. They can answer all your questions.