Brinell Hardness Number Calculator

About this calculator

The Brinell hardness test presses a hardened steel or tungsten-carbide ball of known diameter into a material under a fixed load (typically 500–3000 kgf), then measures the diameter of the resulting indentation. The Brinell Hardness Number is HB = 2P ÷ (πD(D − √(D² − d²))), where P is the load, D is the ball diameter, and d is the measured indentation diameter — a larger indentation for the same load means a softer material.

Because the ball leaves a relatively large, averaged impression, Brinell testing is preferred over Rockwell or Vickers for coarse-grained or non-uniform materials such as castings, forgings, and thick steel plate, where a small indenter could land on a single grain or inclusion and skew the result. Metallurgists, quality-control inspectors, and foundries use it under ASTM E10 or ISO 6506 to verify that incoming stock or finished parts meet a specified hardness range before shipping or further machining.