On a few metal hardness instruments, major equipment is on a different angle conical diamond indenter or different diameter ball pressure on the first loading of the metal to Surface make indentation.

It is suggested to apply the principle of effective gravity and equivalent pressure head to calculate the rotational speed and ingate area in the processing of grinding ball by centrifugal casting.

The pressure distribution curve and the influence of the angle of head are tested and analyzed using steel ball qua solid granules pressure-carrying medium through experiments.