A cutter assembly has a crossbar, cutter blades, and blade pins. The crossbar defines bar openings. Each cutter blade defines a blade bolt opening and first and second blade edges. The blade pins are each adapted to be inserted through one of the bar openings and one of the blade bolt openings such that the head portions of the blade pins are within one of blade recesses of the cutter blades. Bolt key surfaces of the blade pins engage bar key surfaces of the crossbar to prevent rotation of the blade pins relative to the crossbar. The cutter blades are each operable in first and second configurations, where the first blade edges are in a leading position in the first configuration and the second blade edges are in a leading position in the second configuration.