How to read and represent a Brinell hardness value

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A Brinell hardness value consists of the following components:

1. The numeric hardness value;

2. The three letters "HBW", standing for "Hardness according to Brinell" (with hard metal ball made from tungsten carbide);

3. The ball diameter in mm;

4. The applied test load in kgf;

5. According to ISO 6506: The dwell time of the test load, but only if this is not between ten and 15 seconds (uncommon in practice)


210 HBW 5/250/30

  • 210 …hardness value
  • HBW …as per Brinell with tungsten carbide ball
  • 5 …with ball diameter of 5 mm
  • 250 …with test load of 250 kgf (or test force of 2.452 kN )
  • 30 …dwell time to test force outside recommended duration, in this case: 30 seconds