BLADE-MOWER, XHT, 19-3/8", 13/32, Center Hole: 13/32", Outer Hole: 5/16", Width: 2", 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.