Ariens OEM Replacement Blade 310-045
Requires 2 for 32'' desk;
3 for 48'' desk; notched air lift blade
Length 16 1/4'' (412.8mm) 
Centre Hole 5/8'' (15.9mm)
Outer Hole 1/4'' (6.4mm)
Centre 1 5/8'' (41.3mm) 
Width 2 1/2'' (63.5mm)
Thickeness .250 (6.4mm)