In the past, manufacturers who needed to test the hardness of various metals according to different test methods and scales were forced to buy separate pieces of equipment or use conversion scales to determine approximate hardness.
These manufacturers primarily used the Brinell, Rockwell and Vickers methods to test hardness. Brinell is used to test large parts such as castings and forgings of low to medium hardness. With the Brinell, a known load is applied for a given length of time to the surface of the specimen with a hardened steel or carbide ball. The diameter is measured and compared to known conversion scales.