The grinding process is a key step in the production of steel balls for ball bearings. It is one of the last material removal operations in the production chain. It allows the balls to be machined inside the grooves obtained on two discs, plate and grinding wheel. The latter is rotated and pressed against the plate. The combined effect of speed and contact pressure allows the ball to be machined. As one of the last steps before packaging, the quality of the product at the end of this stage is of paramount importance. A high level of control is therefore necessary.