Mtd OEM Replacement Blade 335-624
FITS MODELS: 400 and 600 series, 1997 and newer 
Requires 2 for 38'' deck; mulching blade;
Length 19 1/4'' (489mm)
Centre Hole 6 pt. star
Width 2 3/4'' (69.9mm)
Thickness .149'' (3.8mm)