Abstract: A sanding machine for sanding the surfaces of work pieces placed upon a conveyor operable to transport the work pieces along a first direction is disclosed wherein each of two sanding heads is oscillated at two different frequencies relative to the work pieces on the conveyor. The first oscillating frequency orbits the sanding heads in a circular motion over the work pieces on the conveyor, while the second oscillating frequency, which is greater than the first frequency, results in a vibration of the individual sanding elements engaging the work pieces. Each sanding head includes a plurality of sander elements transversely spaced above the conveyor, the sander elements of the first sanding head being staggered with respect to the sander elements of the second sanding head.