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Vickers Hardness

General

Vickers Hardness (HV)

A material hardness scale using a diamond pyramid indenter, commonly used as the reference scale for converting between other hardness scales like Rockwell and Brinell.

Definition

Vickers Hardness (HV) measures a material's resistance to indentation using a diamond pyramid indenter pressed into the surface under a known load. The size of the resulting indent — specifically its diagonal length — determines the hardness value, with smaller indents indicating harder materials.

Because Vickers hardness applies consistently across a wide range of material hardness (unlike Rockwell, which uses different scales for different hardness ranges), it's commonly used as the reference scale for converting between hardness systems. The Hardness Scale Converter uses Vickers as its internal reference point.

Formula

HV = 1.8544 × (Force ÷ Diagonal²)

Where force is in kilograms-force and the diagonal is measured in millimetres. In practice, hardness testing equipment calculates this automatically from the indent measurement.

Worked Example

A test on hardened tool steel might show a Vickers hardness of around 700 HV, corresponding to approximately 59–60 on the Rockwell C scale using the standard steel correlation table.

Key Things to Know

  • Reference scale for conversions: the Hardness Scale Converter converts between Rockwell, Brinell, Shore D, and Mohs by routing through Vickers internally.
  • Wide applicable range: unlike Rockwell, which switches scales (B, C, etc.) for different hardness levels, Vickers works consistently across soft and very hard materials.
  • Steel-calibrated conversions: standard correlation tables between Vickers and other scales are calibrated for steel specifically.
  • Empirical, not formulaic, cross-scale conversion: converting Vickers to another hardness scale requires a correlation table, not a direct mathematical formula.

Related Terms

CGSCentimetre-Gram-Second System

Frequently Asked Questions

Vickers hardness covers a wide range of material hardness with a single consistent indenter and formula, making it a practical common reference point for converting between other scales like Rockwell and Brinell, which each use different indenters and load ranges.
A diamond pyramid indenter is pressed into a material's surface under a known load, and the resulting indent's diagonal length is measured — smaller indents indicate harder materials.
There's no simple formula — the [Hardness Scale Converter](/hardness-scale-converter/) interpolates against a standard steel-based correlation table (closely following ASTM E140) to estimate the equivalent Rockwell C value.
The standard hardness correlation tables, including Vickers-based conversions, are calibrated primarily for steel — using them for other materials like aluminium or plastics gives only an approximate result.
Soft metals like aluminium fall around 15–120 HV, mild steel around 120–200 HV, hardened tool steel can reach 700–940 HV, and diamond (used as the indenter itself) exceeds 10,000 HV.