The hardness of a material as determined by forcing an indenter such as a Vickers or Knoop indenter into the surface of a material under very light load; usually, the indentations are so small that they must be measured with a microscope. Capable of determining harnesses of different microconstituents within a structure or of measuring steep hardness gradients such as those encountered in case hardening.

(r) hardness measured with an instrument having a smaller indentor and applying a lower force than the standard instrument, permitting measurements on smaller specimens or thinner sheets that are not amenable to measurement by normal instruments.

Hardness of the microscopic areas of a material. [See: Moderate/Severe Dental Fluorosis