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Bess MTI laboratories provide Rockwell and Brinell Hardness measurements for materials evaluation.
The Rockwell Hardness Test
The Rockwell hardness is measured by indenting the test material with a diamond cone or hardened steel ball. The indenter is forced into the test material under a preliminary minor load, followed by incremental addition of a major load. When a permanent increase in depth of penetration is reached, the Rockwell Hardness number, RH can be calculated using the equation:
where E is a constant depending on form of indenter and e is the permanent increase in depth of penetration due to major load F measured in units of 0.002 mm.
The Brinell Hardness Test
The Brinell hardness test method consists of indenting the test material with a 10 mm diameter hardened steel or carbide ball subjected to a load, selected according to the material, for a period of a few seconds.
The diameter of the indentation left in the test material is measured with a low powered microscope. The Brinell harness number, BH is given by the ration of the applied and the surface area of the indentation, according to the equation:
Where F is the applied load on kgf and D is the diameter of the indentation in mm.
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