This knife is the end-mounted cutting element on the cutterbar of a grain harvester header. It operates at the outermost position of the knife section, where it initiates the cut against the stationary guard. A worn or broken end knife leaves a ragged stubble line and increases the draft force on the header, which can lead to uneven feeding into the auger. The manufacturer machines this component to match the original hole pattern and thickness so it seats flush against the knife back without shimming. On installation, use the correct bolt torque and replace any worn wear plates on the mating guard.