Brinell Hardness Testing

Brinell Hardness

The brinell  hardness testing method is the first method invented for standardising hardness, from which other hardness measurement methods have been derived. Brinell hardness is the test force F divided by the contact area S (mm2) between the spherical indenter and the specimen calculated on the diameter d (mm) of the impression made when the indenter (a steel ball or cemented carbide ball with a diameter D mm) is pressed into the sample using a test force F and then removed. The symbols HBS is used when the indenter is a steel ball and HBW when the indenter is a cemented carbide ball. K is a constant (1/g=1/9.80665+0.102).

The same loading conditions (F/ ), the brinell hardness test obtained is almost the same for different hardness loads applied. In many countries tesing with small test loads is common as an application of this fact.  Testing with a test load of 2451 N or less can be conducted using the test load of a Vickers or Rockwell tester. For steel F/  = 30. For other softer materials an appropriate value is selected from 15,10,5,2.5,1.25 and 1. In JIS and ISO standards, the test force is 9.807 to 29420N, and the diameter of the spherical indenter is 1 to 10mm.