Abstract: Apparatus for crushing chunks of trees and tree stumps comprising a solid cylinder having cutting elements extending from the surface. The housing containing the cylinder is provided along one side wall with stationary cutters extending out toward the surface of the cylinder between the columns of the cutting elements which are moving as the cylinder rotates. The space between the stationary cutters and the surface of the cylinder is adjustable in order to be able to select the size of particles being produced. A conveyer beneath the housing carries away the particles. The cutting elements are mounted in such away as to permit easy replacement in the event of a failure. Means are provided to drive said cylinder at no more than 50 RPM.