NEWS | 25.04.2023

Brinell, Rockwell & Vickers
An overview of hardness testing

Hardness tests have been performed on most materials, and especially metals, in one form or another for more than 250 years and provide important information about the properties of a material.

Hardness test according to Rockwell (HR)

The Rockwell hardness test was developed by Professor Paul Ludwik of Vienna as early as 1908. However, the process did not achieve commercial significance until around 1914, when the brothers Stanley and Hugh Rockwell further developed it and filed a patent application.

Rockwell is an internationally used unit of measurement for the hardness of technical materials. The abbreviation HR stands for Hardness Rockwell and is used to identify the test method. HR is followed by another letter, which indicates the scale, testing force and test specimen.

The test method measures how deeply a test specimen penetrates the material.

Hardness test according to Rockwell C (HRC)

The Rockwell hardness test C (HRC) is the most commonly used hardness test in Europe. A diamond cone exerting a force of 1471N (150kg) is pressed into the material being tested. The hardness is determined by measuring the penetration depth of the diamond cone.

  • HRC for testing hard materials and large specimens (testing force 150kg)
  • Standards: ASTM E18, DIN EN ISO 6508-1
Impressions of Rockwell hardness test (HRC)
Diamond cone

Hardness test according to Brinell (HB)

La méthode d'essai de dureté développée par l'ingénieur suédois Johan August Brinell en 1900 et présentée à l'Exposition universelle de Paris est utilisée pour les métaux doux à moyennement durs, comme l'acier de construction non allié, les alliages d'aluminium, le cuivre et les alliages de cuivre.

Une bille en carbure de tungstène est enfoncée avec une force d'essai F dans la surface de la pièce à contrôler.

Le contrôle s'effectue au moyen d'un appareil de mesure qui presse une bille de carbure de tungstène dans la surface de l'échantillon. L'impression qui en résulte est mesurée visuellement.

  • Pour tester la dureté des matériaux doux à mi-durs
  • Standards: ASTM E10, ISO 6506-1 à 6506 -4
Impressions of Brinell hardness test (HB)
Tungsten carbide ball

Vickers hardness test (HV)

This hardness test was developed by Smith and Sandland in 1925 and named after the British engineering company Vickers. It is used to test homogeneous materials and thin-walled or surface-hardened materials and marginal zones
 
Unlike Rockwell testing, an equilateral diamond pyramid with an opening angle of 136 degrees is penetrated into the workpiece under a specified force. The indentation area is calculated by measuring the length of the diagonal of the permanent indentation using a measuring microscope. The Vickers hardness value is determined by dividing the applied load (N) by the surface area of the indentation.
 
  • For testing the hardness of soft to hard materials
  • Standards: ASTM E92 / E384, ISO 6507-1 to 6506 -3

 

Impressions of Vickers hardness test (HV)
Diamond pyramid

Conversion of different hardness values and tensile strength

The conversion is subject to inaccuracies and results only in approximate values.

Hardness comparison tables

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In our in-house materials laboratory, our team of materials engineers will be happy to conduct hardness tests on your materials using appropriate methods. We also test materials from third-party suppliers.

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