“HDT” test means The test determines the temperature at which a specified deflection occurs when a standard test specimen is subjected to a bending stress, to produce one of the nominal surface stresses according to international standards. This test is important for both quality control and research into plastics.
“VICAT” test means The test determines the temperature at which a standard indenter penetrates 1mm into the surface of a test specimen under load. It is used to establish the difference between many types of thermoplastic materials with regard to their softening properties.
ISO 75,ISO 306,ASTM D 1525,ASTM D 648 and the equivalent.