For metals, methods involving static force application are usually employed. An indenter (ball, cone or pyramid) made of carbide or diamond is pressed vertically into the surface of a specimen supported on a firm base. The test load is applied smoothly and without impact, with defined application and dwell times. In many test methods the indentation is measured following load removal. The length measurement values (indentation depth, diagonals, diameter) and test load are used to calculate the hardness value.
In practice, the Rockwell, Brinel and Vickers and Knoop hardness testing methods are used, with the modern instrumented indentation method (Martens hardness) gaining steadily in significance. This method is seeing increasing use, particularly in research and development and industry, as it provides additional parameters for determining material properties as well as the hardness value. Moreover, this method can be employed with any material.
Methods featuring dynamic force application often require mobile devices, particularly when large components are being tested.