(3 Pack) Encore / Worldlawn Premium Replacement 18" x 2 &frac12;" Notched Lawn Mower Deck Blade | 823004 This is a Brand New 3 Pack Premium Replacement Lawn Mower Deck Blade! Top Quality Premium Replacement Replacement Part! Center Hole 5/8" Length 18" Thickness .197" Width 2 1/2" 36" Cut Using 2 Blades; 52" Cut Using 3 Blades Replacement XHT Lawnmower blade. XHT(Xtreme Hardness & Toughness) blades are 25-40% harder than standard lawnmower blades. Benefits of the HXT blade are sharper and longer lasting cutting edges. More resistance to bending. Tighter tolerances in the aftermarket vs. OEM. XHT blades also offer greater impact toughness.