Rockwell Hardness testers
As explained into “Rockwell Hardness Test” article, to ensure accuracy and consistency, look the Major Load must to be under precise control and the penetrators are manufactured to specific tolerances.  Rockwell testing differs from Brinell testing in that the Rockwell hardness number is based on an inverse relationship to the measurement of the additional depth to which an indenter is forced by a heavy (major) load beyond the depth resulting from a previously applied (minor) load.

Each point of hardness on the regular (R) scale is 0.00008 inch and 0.00004 inch on the superficial (S) scale, making the need for precise control of the applied forces and precision manufacture of the penetrators readily apparent. The simplicity in the operation of a Rockwell hardness machine has provided the added advantage that Rockwell hardness testing usually does not require a highly skilled operator.

Many of today’s newer Rockwell Hardness Testers automatically perform the entire Rockwell test cycle. Some of Bench-top Hardness Testers are fully automated to drive the application of the forces at a higher rate than was typical for a person. The increased rate of testing is considered important for production testing, but the automated operation removes much of the control by the user. Depending on the machine model, the responsibility of the operator can vary from manually applying and controlling each of the test forces to simply pushing a button.