Vicat softening point or Vicat hardness is the determination of the softening point for materials that have no definite melting point , such as plastics . It is taken as the temperature at which the specimen is penetrated to a depth of 1?mm by a flat-ended needle with a 1 square mm circular or square cross-section. For the Vicat A test, a load of 10 N is used. For the Vicat B test, the load is 50 N.
Standards to determine Vicat softening point include ASTM D 1525 and ISO 306, which are largely equivalent. Property information for specific grades of resin are available in the Prospector Plastic Database. Property Search let’s you search for plastics by more than 400 material properties. Vicat Softening Temperature – ISO 306
The temperature at which a 1mm2 flat-ended needle will penetrate 1mm into a material under a specified load and heating rate. The vicat softening temperature can be used to compare the heat-softening characteristics of different materials.