Brinell [HB] is one of the most common units used for listing the hardness of steel materials. the test is done with a 10 mm steel ball pressed with 3000 Kgf (6,614 Lbf). Common values for machined materials range from 100 HB for very soft materials up to 650 HB for heat-treated steels.
The advantage of Brinell [HB] over Rockwell [HRC/HRB], is that the whole range is covered on the scale, whereas in the Rockwell C scale, when the hardness is below 180 HB, you must switch to Rockwell B.
