This serrated knife is the cutting element mounted on the rotor of the straw chopper. It severs the straw stream after the crop has passed through the threshing mechanism, reducing material length for even spreading behind the combine. The serrated edge creates a tearing action that requires less cutting force than a straight edge, which helps maintain rotor speed under heavy straw loads. A dull or worn knife leaves uncut straw strands that can form clumps on the field surface. The manufacturer machines the mounting hole and thickness to match the original rotor carrier, so the knife seats flush against its support bar without shimming. When replacing, inspect the carrier slots for wear and tighten the retaining bolts to the specified torque.