Oregon 192-104 Replacement Blades for 48 John Deere GX21784, GX21785. Replaces old Oregon Number 92-104. Center Hole Size – 7 pt. Our OregonĀ® 100 Series lawn mower blade is made from Boron steel, which allows for the perfect balance of durability and ductility. With the Ultra X-tended Cutting LengthT, the 92-104 has improved cutting efficiency per rotation. The double bevel technology helps reduce overall blade noise by up to 1.5 decibels. Requires 3 blades for 48 cut. Resists bending, breaking and fracturing. Major brand replacement: John Deere. John Deere AM137757, AM137758, AM141035, AM141036, GX21784, GX21785, GX21786, GY20852.