Rockwell hardness test is performed by forcing an indenter of specified material, size and shape under the application of known force to produce an indentation in the material. The most common test loads are 60kgf, 100kgf and 150kgf. The depth of indentation is proportional to the hardness of material. The hardness testing machine indicates direct value of hardness by measuring depth of indentation under preliminary test force.

AS 1815, ISO 6508 and ASTM E18 are some of the common standard test methods.