Hardness Conversion Table

Hardness Conversion Table is a practical reference tool designed to help engineers, inspectors, technicians, and quality control professionals accurately compare and convert material hardness values across different international testing standards. It provides clear correlations among commonly used hardness scales, such as Rockwell, Brinell, Vickers, and Shore, enabling users to interpret test results without complex calculations quickly. This ensures a consistent understanding of material properties when working with specifications, drawings, inspection reports, or supplier data from different regions or industries.

The table supports efficient decision-making in material selection, heat-treatment verification, machining process control, and quality assurance by reducing the risk of misinterpretation across hardness systems. It is widely used in manufacturing, metal fabrication, automotive, aerospace, mechanical engineering, and educational environments where precise material evaluation is essential.

The Hardness Conversion Table is an essential reference for professionals who require reliable comparisons of hardness values, improved communication across standards, and accurate assessments of material strength, wear resistance, and performance in industrial and engineering applications.

Vickers
Hv		 HB Rockwell Rockwell Superficial Shore
Hs		 Temsile
Stemgth
KG/mm2
HRA HRB HRC HRD 15-N 30-N 45-N
940 85.6 68.0 76.9 93.2 84.4 75.4 97
920 85.3 67.5 76.5 93.0 84.0 74.8 96
900 85.0 67.0 76.1 92.9 83.6 74.2 95
880 84.7 66.4 75.7 92.7 83.1 73.6 93
860 84.4 65.9 75.3 95 82.7 73.1 92
840 84.1 65.3 74.8 92.3 82.2 72.2 91
820 83.8 64.7 74.3 92.1 81.7 71.8 90
800 83.4 64.0 73.8 91.8 81.1 71.0 88
780 83.0 63.3 73.3 91.5 80.4 70.2 87
760 82.6 62.5 72.6 91.2 79.7 69.4 86
740 82.2 61.8 72.1 91.0 79.1 68.6 84
720 81.8 61.0 71.5 90.7 78.4 67.7 83
700 81.3 60.1 70.8 90.3 77.6 66.7 81
690 81.1 59.7 70.5 90.1 77.2 66.2
680 80.8 59.2 70.1 89.8 76.8 65.7 80
670 80.6 58.8 69.8 89.7 76.4 65.3
660 80.3 58.3 69.4 89.5 75.9 64.7 79
650 80.0 57.8 69.0 89.2 75.5 64.1
640 79.8 57.3 68.7 89.0 75.1 63.5 77
630 79.5 56.8 68.3 88.8 74.6 63.0
620 79.2 56.3 67.9 88.5 74.2 62.4 75
610 78.9 55.7 67.5 88.2 73.6 61.7
600 78.6 55.2 67.0 88.0 73.2 61.2 74
590 78.4 54.7 66.7 87.8 72.7 60.5 210
580 78.0 54.1 66.2 87.5 72.1 59.9 72 206
570 77.8 53.6 65.8 87.2 71.7 59.3 202
560 77.4 53.0 65.4 86.9 71.2 58.6 71 199
550 (505) 77.0 52.3 64.8 86.6 70.5 57.8 194
540 (496) 76.7 51.7 64.4 86.3 70.0 57.0 69 190
530 (488) 76.4 51.1 63.9 86.0 69.5 56.2 186
520 (480) 76.1 50.5 63.5 85.7 69.0 55.6 67 183
510 (473) 75.7 49.8 62.9 85.4 68.3 54.7 179
500 (465) 75.3 49.1 62.2 85.0 67.7 53.9 66 174
490 456 74.9 48.4 61.6 84.7 67.1 53.1 169
480 448 74.5 47.7 61.3 84.3 66.4 52.2 64 165

 

Material hardness is a measure of a material’s resistance to deformation, particularly permanent indentation, scratching, cutting, or abrasion. It’s a critical property in selecting materials for engineering, tooling, gears, and wear-resistant applications. There are different types of hardness depending on what kind of resistance you’re measuring:

 

 

Types of Hardness

 

 

  1. Scratch Hardness

    • Resistance to being scratched or cut.

    • Measured by the Mohs scale (used for minerals).

  2. Indentation Hardness

    • Resistance to permanent deformation from a fixed load.

    • Most common in metals and industrial components.

    • Measured by:

      • Brinell Hardness (HBW)

      • Rockwell Hardness (HRC, HRB, etc.)

      • Vickers Hardness (HV)

  3. Rebound Hardness

    • Measures elasticity by how high a dropped object bounces off the material.

    • Measured by Shore scleroscope (used less commonly).

 

 

Common Hardness Testing Methods

 

 

Method Application Typical Scale How It Works
Brinell (HBW) Soft–medium metals 100–600 HBW A steel ball is pressed into the material; a large indent = softer
Rockwell (HRC/HRB) General metals 20–70 HRC Cone or ball indenter; depth of penetration is measured
Vickers (HV) Thin or small parts 100–1000+ HV Diamond pyramid indenter; very precise
Mohs Minerals, coatings 1–10 Scratching test using standard reference minerals

 

Comparison Example

 

 

Material Brinell (HB) Rockwell (HRC) Vickers (HV) Mohs
Soft steel ~120 — ~130 ~4
Hardened tool steel ~600 60–65 HRC ~800 ~8.5
Titanium ~200 30–40 HRC ~300–400 ~6
Glass — — — ~6.5
Diamond (hardest) — — — 10

 

Why Hardness Matters

 

 

  • Wear resistance: Harder materials resist wear better (critical for gears, dies, cutting tools).

  • Machinability: Very hard materials are difficult to cut or drill.

  • Fatigue and strength: Generally, higher hardness can correlate with higher tensile strength.

  • Heat treatment effect: Many metals (like steel) are heat-treated to raise hardness via surface or through-hardening.

 

 

Hardness in Gears and Mechanical Parts

  • Gear teeth are often surface-hardened (e.g., via carburizing, nitriding, or induction hardening) to combine a hard, wear-resistant surface with a tough, ductile core.

  • Typical gear surface hardness:

    • Carburized steel: 58–62 HRC

    • Induction hardened: 50–60 HRC

    • Nitrided steel: ~1000–1200 HV

 

 

Material hardness is not the same as strength, toughness, or brittleness, but it’s closely related. The proper hardness depends on what your part needs to do — whether it must resist wear, endure impact, or tolerate bending.