Step 4: Install the New Blade
Most mower designs will not allow the mower blade to be installed with the wrong side down.
Our example mower blade and its retaining plate are shaped so that the blade can only be installed in the correct position
It is possible to incorrectly install mower blades on some mowers. And it's always possible to install a blade too loosely.
Vibration and poor lawn cutting will quickly make a poor mower blade installation noticeable. A quick adjustment is all it takes to get back to work in the event of an incorrect installation.