What Is Rockwell Hardness?

Rockwell hardness is an index used to determine the hardness value of the depth of plastic deformation of indentation, with 0.002 mm as a hardness unit. In Rockwell hardness test, using different indenters and different test forces will produce different combinations, corresponding to different Rockwell hardness scales. There are three rulers in common use, and their applications cover almost all commonly used metal materials.