Others correctly pointed out the shear pin snapped to protect the snow
blower. I would pay attention to the grade of shear bolt you are
replacing with. Use the same grade of bolt, likely 8.8 (carbon steel
which is softer, not alloy steel, grade 10.9). My guess is the
replacement bolt from Sears will be much more expensive. You can get
the same size and grade bolt for pennies at Home Depot.