Knoop hardness (KH),
Definition of Knoop hardness (KH):
Material hardness test in which the depth (and not the area) of indent caused by the impact of a highly polished and elongated pyramidical (pointed rhombohedral) diamond is measured. KH is expressed as a ratio of the applied force in kilograms and the depth of penetration in millimeters.
Meaning of Knoop hardness (KH) & Knoop hardness (KH) Definition