Explanation of hardness of wear resistant steel balls

1. Brinell hardness (HB)

Hardened steel balls of a certain size (usually 10 mm in diameter) are pressed into the surface of the material under a certain load (generally 3000kg) for a period of time. After unloading, the ratio of load to indentation area is called Brinell hardness value (HB) in kilogram force/mm2 (N/mm2).

2. Rockwell hardness (HR)

When HB>450 or specimen is too small, Brinell hardness test and Rockwell hardness test can not be used. It is a diamond cone with a top angle of 120 degrees or a steel ball with a diameter of 1.59 and 3.18 mm. It is pressed into the surface of the material under certain load, and the hardness of the material is calculated from the depth of the indentation.

3. Vivtorinox hardness (HV)

The surface area of indentation pit is divided by the load value, that is, the Vickers hardness HV value (kgf/mm2).