The Rockwell method utilises 5 different indenters (diamond cone, 1/16",1/8",1/4",1/2" tungsten carbide ball) and 6 different main loads (15, 30, 45, 60, 100, 150 kgf). This totals 30 different Rockwell scales, each one of them characterised by a different combination of indenter type and main load, and each one suitable for a particular material/application. (ex. HRA, HRB, HRC, HR30N etc.).
Rockwell is often used as a "quick test" on the production floor or in the laboratory, but is also used for more advanced tests, such as the Jominy (end quench) test (HRC).
The Rockwell methods are described by a number of scales characterized by a standard, an indenter type, and a load.
- HRE 1/8-inch diameter tungsten carbide ball indenter, 100 kgf major load
- HR30N (Superficial Rockwell 30N-scale): Diamond cone indenter, 30 kgf major load
Overview of typical applications for Rockwell Scales