This rotary chopper knife is a cutting element for the straw chopper assembly on a forage harvester. It is mounted on the chopper rotor and severs crop material as it passes through the cutting chamber. The knife interacts with a stationary shear bar to produce a clean cut; a dull or worn knife increases the power draw of the rotor and produces ragged, unevenly sized particles. As an original-manufacturer component, its mounting-hole geometry and edge profile match the rotor's bolt pattern and the shear-bar clearance specified for the assembly. When replacing a knife, inspect the shear bar for wear and replace it if the gap between the bar and the new knife exceeds the recommended clearance.