BLADE-MOWER, XHT, 22", 59/64X11/16, Center Hole: 59/64 x 11/16", Outer Hole: 5/16", Width: 2-1/4", C to C: 2-1/2", Type: Medium Lift - Notched, Web Notes: Replacement XHT Lawnmower blade. XHT(Xtreme Hardness & Toughness) blades are 25-40% harder than, Web Notes: standard lawnmower blades.