1. What is Brinell hardness?
Brinell hardness refers to that the cemented carbide ball with diameter D is pressed into the surface of the material with the corresponding test force F, the test force is removed after being maintained for a specified time, the average diameter of the residual indentation is measured with a reading microscope, and the hardness value is expressed by the pressure on the unit area of the spherical crown indentation.
HB=0.12*F/S(F=KG*9.8;S=π*D*h)
According to the Pythagorean law of diameter and indentation diameter, it can be converted to:

2. Brinell hardness measurement is adopted. Due to the large residual indentation area, it can truly reflect the average hardness of the material, and the measurement data is stable. Therefore, it is used to measure the material with coarse or uneven structure (cast iron).