Vicat Softening Temperature ASTM D1525, ISO 306

Scope:
The Vicat softening temperature is the temperature at which a flat-ended needle penetrates the specimen to the depth of 1 mm under a specific load. The temperature reflects the point of softening to be expected when a material is used in an elevated temperature application.

Test Procedure:
A test specimen is placed in the testing apparatus so that the penetrating needle rests on its surface at least 1 mm from the edge. A load of 10N or 50N is applied to the specimen. The specimen is then lowered into an oil bath at 23 degrees C. The bath is raised at a rate of 50° or 120° C per hour until the needle penetrates 1 mm. 

Specimen Size:
The test specimen must be between 3 and 6.5 mm thick and at least 10 mm in width and length. No more than three layers may be stacked to achieve minimum thickness. 

Data:
Temperature at which the needle penetrates 1 mm. 

Equipment used:
Atlas HDV2 DTUL/ Vicat tester

**Please note that this test description is intentionally generic in nature and aimed at providing a descriptive summary to enhance test understanding. Standards can be obtained from appropriate standard authorities.