Vicat Softening Temperature - ASTM D1525
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.
Two different heating rates and two different loads may be used for testing.
Heating Rate A: 50°C/hr
Heating Rate B: 120°C/hr
Loading 1: 10 N (1 kg)
Loading 2: 50 N (5 kg)