An object’s hardness should be classified as a feature or a characteristic rather than one of its properties and the hardness is generally measured by calculating the permanent area of the indentation caused by a fixed load.
The Rockwell hardness test is one of the most basic and effective methods of hardness testing of different materials. It was invented by Stanley P. Rockwell in 1919 for determining the accurate and speedy measurement of hardness.
Rockwell hardness testing is the most commonly used method for assessing the hardness of specimens. Under this method, the hardness of the specimen is measured by assessing the depth of the indentation made by the indenter under the test load on the specimen surface.