Hardness Conversion Charts


Hardness tests are not strictly comparable - each type of test measures the resistance to deformation of the material in slightly different ways. However, it is still possible to make useful approximate comparisons between hardness scales, and some are presented here.

All values are plotted against HV - Vickers Hardness (also known as Diamond Pyramid Hardness) - Pyramidic Diamond Indentor, 10kgf Load.

Steels (Low Hardness, HV < 300)
  • HRB - Rockwell Hardness B Scale - 1/16" Ball Penetrator, 100kgf Load
  • HRE - Rockwell Hardness E Scale - 1/8" Ball Penetrator, 100kgf Load
  • HRF - Rockwell Hardness F Scale - 1/16" Ball Penetrator, 60kgf Load
  • HRG - Rockwell Hardness G Scale - 1/16" Ball Penetrator, 150kgf Load
  • HRH - Rockwell Hardness H Scale - 1/8" Ball Penetrator, 60kgf Load
  • HRK - Rockwell Hardness K Scale - 1/8" Ball Penetrator, 150kgf Load
  • HR15T - Rockwell Superficial 15-T Scale - 1/16" Ball Penetrator, 15kgf Load
  • HR30T - Rockwell Superficial 30-T Scale - 1/16" Ball Penetrator, 30kgf Load
  • HR45T - Rockwell Superficial 45-T Scale - 1/16" Ball Penetrator, 45kgf Load
Steels (High Hardness, 200 < HV < 2000)
  • HRA - Rockwell Hardness A Scale - Brale Penetrator, 60kgf Load
  • HRC - Rockwell Hardness C Scale - Brale Penetrator, 150kgf Load
  • HRD - Rockwell Hardness D Scale - Brale Penetrator, 100kgf Load
  • HR15N - Rockwell Superficial 15-N Scale - N Brale Penetrator, 15kgf Load
  • HR30N - Rockwell Superficial 30-N Scale - N Brale Penetrator, 30kgf Load
  • HR45N - Rockwell Superficial 45-N Scale - N Brale Penetrator, 45kgf Load
  • HSc - Shore Schleroscope Hardness Number
Steels (High Hardness, 200 < HV < 2000)
  • HB10/500 - Brinell, Standard Type - 10mm Ball Penetrator, 500kgf Load
  • HB10/3000, Standard - Brinell, Standard Type - 10mm Ball Penetrator, 3000kgf Load
  • HB10/3000, Hultgren - Brinell, Standard Type - Hultgren 10mm Ball Penetrator, 3000kgf Load
  • HB10/3000,WC - Brinell, Standard Type - Tungsten-Carbide 10mm Ball Penetrator, 3000kgf Load
  • HK - Knoop Hardness - Pyramidal Diamond Indentor, 500gf Load
Aluminium Alloys and Brasses
  • HRB - Rockwell Hardness B Scale - 1/16" Ball Penetrator, 100kgf Load
  • HRF - Rockwell Hardness F Scale - 1/16" Ball Penetrator, 60kgf Load
  • HB10/500 - Brinell, Standard Type - 10mm Ball Penetrator, 500kgf Load
  • HB10/1000 - Brinell, Standard Type - 10mm Ball Penetrator, 1000kgf Load
  • HR15T - Rockwell Superficial 15-T Scale - 1/16" Ball Penetrator, 15kgf Load
  • HR30T - Rockwell Superficial 30-T Scale - 1/16" Ball Penetrator, 30kgf Load
  • HR45T - Rockwell Superficial 45-T Scale - 1/16" Ball Penetrator, 45kgf Load
  • HR15T - Rockwell Superficial 15-T Scale - 1/16" Ball Penetrator, 15kgf Load
  • HR30T - Rockwell Superficial 30-T Scale - 1/16" Ball Penetrator, 30kgf Load
  • HR45T - Rockwell Superficial 45-T Scale - 1/16" Ball Penetrator, 45kgf Load