The Rockwell, Brinell, and Vickers Hardness Tests are among several different Hardness Test Methods. The Rockwell test method is the most commonly used hardness test method. It is generally easier to perform and more accurate than other types of hardness testing. Unlike the Brinell and Vickers tests, where the size of the indentation is measured following the indentation process, the Rockwell hardness of the material is based on the difference in the depth of the indenter at two specific times during the testing cycle.