Heat Deflection Temperature (HDT) of plastics

Heat deflection temperature (HDT), also known as heat distortion temperature, describes the plastic's resistance to deformation by a given load at an elevated temperature. It can also give insight into the injection mouldability of the plastic.

HDT is defined as the temperature where the sample specimen bends 0.25 mm under a given weight. It can be measured with either method A (1.80 MPa), B (0.45 MPa), or C (8.00 MPa) as per ISO 75.

The load and specimen type are chosen according to the tested material. The test is always done as a duplicate.

Suitable sample matrices
Rigid plastics
Required sample quantity
2 specimens
Typical turnaround time
3 weeks after receiving the samples
Available quality systems
Accredited testing laboratory

Pricing and online order

Price per sample (Excl. VAT):
214 €

We also charge a 97 € service fee per order.

Large batches of samples are eligible for discounts.

Samples are entered during checkout.

Our experts review all orders to ensure the testing method is suitable for your needs and samples.

Questions? We're happy to help.

Questions? We're happy to help.

Ringing phone
...and more than 700 other happy clients

Ask for an offer

Fill in the form, and we'll reply in one business day.

Answering the following questions helps us prepare an offer for you faster:

  • How many samples do you have and what is the sample material?
  • Do you have a recurring need for these tests? If yes, how often and for how many samples at a time?

Have questions or need help? Email us at or call +358 50 336 6128.