The present disclosure relates to a material reducing machine convertible between a grinding configuration and a chipping configuration. The material reducing machine includes a rotary component that is rotatable about an axis of rotation, the rotary component defining a grinding configuration boundary that extends at least partially around the axis of rotation. The material reducing machine also includes a plurality of hammers secured to the rotary component, the hammers including end portions that project outwardly beyond the grinding configuration boundary of the rotary component. Furthermore, the material reducing machine includes a boundary enlarging structure that mounts over the rotary component, the boundary enlarging structure defining a chipping configuration boundary that extends at least partially around the axis of rotation when the boundary enlarging structure is mounted over the rotary component, the chipping configuration boundary being positioned outside the grinding configuration boundary. The boundary enlarging structure is not mounted over the rotary component when the material reducing machine is in the grinding configuration and the boundary enlarging structure is mounted over the rotary component when the material reducing machine is in the chipping configuration.