Vickers Hardness Number Calculator

The Vickers test uses a diamond pyramid indenter for hardness across all materials.

How the Math Works

The Vickers Hardness Number (HV) is calculated using the formula HV = 1.8544·F ÷ d², where F represents the applied force in kilograms-force (kgf) and d is the average diagonal length of the indentation made on the material's surface in millimeters. The constant 1.8544 is derived from the geometry of the Vickers diamond indenter, which creates a square-based pyramid with a face angle of 68 degrees. The diagonal measurement d is typically averaged from two opposite diagonals of the four-sided indentation to account for any asymmetry. Squaring the diagonal length ensures the calculation accounts for the area over which the force is distributed, providing a standardized measure of the material's resistance to deformation.

Practical Applications

To use this calculator in practice, first apply a known force using a Vickers hardness tester to create an indentation on the material's surface. After the material cools, measure the length of the diagonal lines formed by the diamond indenter using a microscope or optical measurement system. Enter the applied force (in kgf) and the average diagonal measurement (in mm) into the calculator. The result gives you the HV value, which allows you to compare the hardness of different materials or track changes in hardness due to heat treatment, wear, or material composition variations. This is commonly used in quality control for metals, ceramics, and coated materials.

Day-to-Day Use

Understanding a material's Vickers hardness helps you make informed decisions in everyday applications involving metal parts and components. When selecting materials for projects at home or work, knowing the HV value helps you choose the right alloys for environments requiring wear resistance, such as cutting tools, automotive parts, or protective coatings. It also helps predict how materials will behave under stress — harder materials resist scratching and deformation better but may be more brittle. By calculating HV values, engineers and manufacturers can ensure product durability, prevent premature failure, and extend the lifespan of mechanical components in everything from smartphones to construction equipment.

Worked example

10 kgf, 0.5 mm diagonal → about 74 HV.

FAQ