How to sharpen a lawnmower blade with a hand file:

1) First, secure the lawnmower blade in a bench vise. Clean it up with a stiff brush then wipe it clean with a soft cloth before sharpening.

2) Use a Grobet 31.157 10" Cut 2 hand file to sharpen the edge of your blade to a 45° angle.

3) Follow the edge of the blade in one direction (not back and forth) while applying a little pressure—you should feel the file teeth biting into the blade.

4) Smooth out rough spots and nicks on the blade.

5) The blade should be about as sharp as a butter knife.

6) When one side of the blade is sharp flip it over and sharpen the other edge.