This bolt secures the straw chopper assembly to the rotating drum on a self-propelled forage harvester. It fastens the chopper knives or counter-knives to their mounting brackets, holding them in position against the cutting forces generated during operation. The bolt is manufactured to a hardness class that resists deformation under the repeated impact loads typical of chopping green crop. A loose or sheared bolt allows the chopper component to shift, which reduces cut quality and can cause imbalance in the rotating assembly. On reinstallation, apply thread-locking compound and tighten the fastener to the specified torque value.