Center Hole Size. The Oregon? 92-033 replacement lawn mower blade is made to the exact OEM specification for optimum performance. Our blades are individually straightened and hardened to provide a consistent, cleaner cut and increase blade longevity. Aggressive blade angle increases air flow to push debris up and out for superior bagging or side discharge. Enhanced mulching for bagging and discharge efficiency. Stays sharp and durable. Major brand replacement: Exmark. Next Lazer Z Air Cooled. Next Lazer Z Propane, Turf Ranger.