Hardness Conversions

Need to produce Brinell hardness values with your Rockwell tester? Hardness conversion makes it possible.

Depending on application and availability, different hardness test equipment is used, each presenting their results in a different hardness-scale (e.g., Vickers, Rockwell or Brinell). Too often there is a need to present the hardness results in a different scale than the scale in which it’s tested. This can be the case when the geometry, dimensions, layer thickness, surface quality, microstructure, or available test equipment dictate the use of a certain scale. Here comes hardness conversion in play.

In the ´70´s and ´80´s, an empirically determined relationship between the various hardness scales was determined. The DIN EN ISO 18265 and ASTM E140 tables are the offspring of this labor intensive research. All Wilson hardness testers have a built in hardness convertor according to DIN EN ISO 18265 and ASTM E140, which automatically shows the converted hardness value next to the original result. Both the values are used for reporting and export.

Foot note:
No reliable information on the uncertainty could be distilled out of the thousands of hardness results used to build DIN EN ISO 18265 and ASTM E140 tables. As a result, no universal conversion relationship was established. For this reason, it is recommended to avoid hardness conversion and to strive to obtain hardness results in their native scale.

Download our Wilson Conversion chart.

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