Hardness test

A test which determines the resistance of the material to deformation.

In the most-common tests, a hard indenter is forced into the surface of the material under a known load for a certain time. When the indenter is removed, the volume of the indentation can be determined and used to produce a hardness number. The three main tests are Brinell, which uses a hard steel or tungsten carbide ball as the indenter; Rockwell, which uses a diamond cone for hard material and a steel or tungsten carbide ball for soft material; Vickers, which uses a diamond pyramid. Generally, steel balls are being replaced as standard by tungsten carbide balls owing to the latter’s reduced likelihood of distortion.

There are many more methods of hardness testing, such as the scratch test, rebound test (scleroscope) and file tests