In practice, the formula is not calculated for every single test in order to determine the hardness value. Alternatively, the hardness value can be read from tables or specially programmed test software, which indicate the hardness value for all standardised ball diameters and test loads as a function of the average indent diameter (d) (see poster "Hardness comparison table").
The test force must be selected such that the average indent diameter (d) is between 0.24 D and 0.6 D.
In order to adhere to these limits, the test force must be coordinated with the ball diameter. This results in different force-diameter indexes (also referred to as loading levels or load factors) within the Brinell method, whereby the quotient of test force and square of the ball diameter is kept constant: B = 0.102*F/D2. The five common force-diameter indexes are 1, 2.5, 5, 10 and 30. Testing of a material with different ball diameters and test forces must be conducted within the same force-diameter index in order to achieve comparable test results (see overview table "Brinell methods and applications").
The ball diameter must be selected in such a way that the indent covers the largest possible workpiece area – representative for the specimen.
According to the standard (ISO 6506), the test load should be increased to its final value within a minimum of two to a maximum of eight seconds Generally, the dwell time for the test load is ten to 15 seconds (s). If the dwell time is any longer, the duration in seconds must also be specified in the hardness value, e.g.: 210 HBW 5/250/30 (dwell time of 30 s).