Brinell Hardness Number

The Brinell Hardness Number calculator computes the hardness factor of a material based on the Brinell Hardness Number equation using the applied load, the diameter of the indenter and the diameter of the indention.

INSTRUCTIONS: Choose units and enter the following:

• (P) Applied Force or Load (Default: 3000 kgf)
• (D) Diameter of tool pressed on material (Default: 10mm)
• (d) Diameter of indentation from the tool

Brinell Hardness Number (BHN): The calculator returns the number in units of kilogram force per square millimeters (kgf/mm²).  However this can be automatically converted to compatible units via the pull-down menu.

The Math / Science

The Brinell Hardness Number characterizes the indentation hardness of materials through the scale of penetration of an indentor, loaded on a material test-piece. Its is one of several definitions of hardness in materials science. The typical test uses a 10 millimeter steel ball as an indentor with a 3,000 kgf (29.42 kN; 6,614 lbf) force. For softer materials, a smaller force is used; for harder materials, a tungsten carbide ball is substituted for the steel ball. The indentation is measured and hardness calculated using the Brinell Hardness Number formula:

    `BHN=(2P)/(piD(D-sqrt(D^2-d^2)))`

where:

• BHN = Brinell Hardness Number
• P = applied load
• D = diameter of indentor
• d = diameter of indentation

References

A helpful Brinell Hardness Number equation tutorial can be found on YouTube at: https://youtu.be/liiopCScMck

The formula and definition are from WIkipedia (https://en.wikipedia.org/wiki/Brinell_scale).