This left-side cutting knife is the blade element mounted on the corn header's gathering chain or deck plate assembly. It severs the stalk at the base before the plant enters the intake rolls. The knife's cutting edge contacts the stalk at a fixed angle determined by the header's geometry; a dull or damaged edge causes ragged cuts that increase shatter loss and plugging risk. This component is manufactured to match the original blade profile so the bolt pattern and edge clearance align with the counter-knife or stationary shear bar on the header. Replace the mounting hardware and check the gap between the knife and the stationary edge during installation.