Vicat softening point
or Vicat hardness
is the determination of the softening point
for materials such as polyethylene
, which have no definite melting point
. 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 sq. mm circular or square cross-section. For the Vicat A test, a load of 9.81 N
is used. For the Vicat B test, the load is 49.05 N.
Standards to determine Vicat softening point include: