Oregon 396-734 Replacement Lawn Mower Blade 20-1/2-Inch Center hole: 7/8" Tungsten carbide is fused into the blade  creating an ultra-hard layer at the cutting edge and increasing the time between sharpening Greater width and thickness extends blade life and allows for longer lifting arch to improve bagging and mulching Major brand replacement: John Deere The aggressive blade angle increases air flow to push debris up-and-out for superior bagging or side discharge