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
Minimum sample amount
2 specimens
Typical turnaround time
3 weeks after receiving the samples
Quality system
Accredited testing laboratory
Method expert
Ville Roininen

Order this test online

First sample (VAT 0):
246 €
Additional samples (VAT 0):
120 €per sample
If you have a large number of samples, contact us for a possible discount.

Samples are entered during checkout.

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

Large number of samples or specialized needs?

Questions? We're happy to help.

Questions? We're happy to help.

Ringing phone

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.