Up for your consideration: John Deere Knife Kit KXE10255 NEW UNOPENED. KXE10255: Chopper Rotor Serrated Knife Kit (8 Wing Blades). Precision grinding guarantees an excellent cutting edge and helps original knives stay within the extremely narrow band of optimum weight tolerances. Original John Deere straw chopper knives are zone hardened, allowing them to withstand higher stress levels. To prevent cracks in the area of the pivot hole, John Deere knives are reamed after punching to ensure loads on the rotor are evenly spread. Original John Deere chopper knives are induction hardened. That’s important for ensuring they can take the truly extraordinary wear and tear they are subjected to, especially at the punched hole and the serrated edges. The process also ensures material elasticity is maintained to eliminatebrittleness.