The Brinell hardness test consists in indenting the metal surface with a 10-mm diameter steel ball at a load of 3,000 kg.
For soft metals the load is reduced to 500 kg to avoid too deep an impression. For very hard metals Tungsten carbide ball can be used to minimize distortion of the indenter. The surface on which the indentation is made should be relatively smooth and free from dirt or scale. (more…)