Abstract: A crushing machine comprises a pair of crushing rolls which are designed to be rotatable towards each other and away from each other. A side plate is provided on the outside of each roll. The crushing rolls have teeth which are shorter than conventional crushing teeth. The teeth on each roll are aligned with each other to provide cavities in which the crushing can occur. Rotation of the crushing rolls towards each other provides a centre sizing action to crush material (e.g. coal) into a larger particle size. Rotation of the crushing rolls away from each other provides a side sizing action to crush material between the roll and the side plates to a smaller particle size. Thus, the machine can crush material into two distinctly different particle sizes without any modification being required to the machine, the dual sizing occurring by reversing the rotation of the rolls.