How does a Rockwell hardness tester work?

The Rockwell hardness tester uses an indenter to press into the surface of a specimen under a certain pressure, and determines the hardness of the specimen based on the depth to which the indenter penetrates the specimen surface. The indenters of the Rockwell hardness tester are divided into three types, which are diamond cones, steel balls, and hard alloy balls, respectively suitable for testing different materials.
The Rockwell hardness tester has 15 combinations of scales, and the appropriate scale can be selected according to different materials and testing requirements. During testing, the specimen is first placed on the workbench of the Rockwell hardness tester, then the indenter is placed onto the specimen surface. After applying pressure for a certain period, the depth of the indenter's penetration into the specimen surface is read, and the Rockwell hardness value of the specimen is obtained through a look-up table or calculation.