The Brinell test, consists of applying a constant load or force, usually between 62.5 and 3000Kgf, for a specified time (from 10 – 30 seconds) using a 2.5, 5 or 10mm diameter tungsten carbide ball. The load time period is required to ensure that plastic flow of the metal has ceased. Lower forces and smaller diameter balls are sometimes used in specific applications. Similar to Knoop and Vickers testing, the Brinell test applies only a single test force. After removal of the load, the resultant recovered round impression is measured across diagonals at right angles and is usually recorded millimeters using a low-power microscope or an automatic measuring device.

The actual Brinell Hardness Number (BHN) is calculated by factoring the indent size and the test force however it is not necessary to make the actual calculation for each test. Calculations have already been made and are available in tabular form for various combinations of diameters of impressions and load. In addition various forms of automatic Brinell reading devices are available to perform these tasks.

Applications: