The hardness test is used in hardening plants for such purposes as quality control and monitoring the heat treatment process. If heat-treated, hardened parts (e.g. gears, shafts, engine blocks, etc.) are tested directly on the production floor, then the hardness testing machine must be robust enough to deliver reliable and reproducible measurement results in the harsh production environment.
Rockwell tests are frequently conducted during the course of production in the manufacturing facility, although low-load and micro hardness testing methods are also used if, for example, the specimens are separated for closer examination before the hardness test.