Should Mower Blades Be Parallel?

The blades should be parallel to each other and perpendicular to the spindle shaft......

Do mower blades have to be lined up?

Do mower blades have to be lined up? Blades are lined up when they are fitted to the new machine and held in place by the spindles and the pins so you should not have to touch them. The way they are set up when they leave the factory is the setting needed to give the best possible cut.

How should mower blades be oriented?

It's important that the blade's cutting edge follows the direction of rotation. The wings of the lawn mower blade will be oriented up toward the mower deck and any writing on the blade will likely be facing away from the deck. If the blade bolt comes with a washer, its concave side will be facing the blade.