The hardness of a material in relation to the penetration of another gives important information about its mechanical and wear properties.
The three most common hardness testing methods with their advantages and disadvantages are explained below.

Härteprüfung nach Brinell (DIN EN ISO 6506-1)
Die Härteprüfung nach Brinell wird bei M&S mit einer gehärteten Stahlkugel an geraden, glatten und zunderfreien Oberflächen durchgeführt.
Sie eignet sich für Prüfobjekte aus weichen bis mittelharten Werkstoffen (<650HB), wie z.B. nicht gehärtete Stähle, Gusseisenwerkstoffe und NE-Metalle.
Das Härteprofil des zu prüfenden Werkstoffs wird mithilfe der durch die Stahlkugel erzeugten Abdrücke bzw. der Verformungen in der Oberfläche ermittelt, die je nach Werkstoffgruppe individuell einwirkenden Kraft und dem vorschriftsmäßigen Beanspruchungsgrad variieren.

Hardnesstest according to Vickers (DIN 6507-1)
The Vickers hardness test is carried out with a diamond pyramid, which has an angle of 136°. This penetrates the workpiece and leaves an impression from which the diagonals are measured and the hardness value obtained is determined taking into account the test force. A straight, smooth, scratch-free and scale-free surface is required for the test.
This hardness testing method is universally applicable and can be used to measure a wide variety of materials and workpieces.
Layers, thin sheets, soft to hardened materials or even individual structural components can be tested.

Hardnesstest according to Rockwell (DIN EN ISO 6508-1)
The hardness test according to Rockwell is mainly carried out with two different test bodies. The diamond cone and the hard metal ball. These also have similar properties and uses to the related Vickers and Brinell test specimens, but have a different shape. A straight surface is required for testing.
The test is carried out with a test pre-force (which penetrates e.g. scale residues before the test starts), then the test is carried out with additional additional force. The hardness is determined from the amount of permanent deformation resulting from the preliminary and additional force.
The diamond cone in the HRC test is similar to Vickers and is suitable for testing hardened, high-strength materials and has an angle of 120°.
Similar to Brinell, the hard metal ball is suitable for testing soft steels and non-ferrous metals.