No matter what type of lawnmower you own, it's important you keep that blade sharp. Otherwise, you risk yanking your lawn instead of slicing it cleanly and healthfully down to size. A sharp blade also keeps your mower running smoothly and shortens the amount of time you spend working on your lawn. The DIY experts at Stack Exchange offer a few tips on keeping your blade sharp, and doing so all by yourself.


Photo by Sean Gallagher.


Is it possible for a DIYer to sharpen the blade on his or her lawn mower? If so, how would I sharpen the blade on my lawn mower? It is a reasonably basic push mower but it does have a 'mulching' blade.


— (Originally asked by Jack)

Answer: 10 Steps

1) Remove the blade by removing the nut that attaches it to the mower.

2) If there is any rust on the blade, remove it with steel wool or a steel brush.


3) Clamp the blade in a vice, or to the edge of a solid work surface.

4) Run a file down the cutting edge, following the same angle already on the blade.









10) Now that your blade is sharpened and balanced, reattach it to the mower.


If you do sharpen the blade using a power grinder, heat from the process can weaken the blade, so you'll want to quench the blade to prevent overheating. Dip the blade in water frequently during the sharpening process to cool it, and wipe it dry before you continue grinding.


Answered by Tester101

Safety Note: Remember Step 0

Make DAMN sure the lawnmower cannot start up while you are removing the blade. I have a relative who is missing a few fingers after he bump-started the motor while trying to remove the nut. Modern machines have better interlocks preventing this sort of thing, but pulling the spark plug and blocking the blade with something thick are also good precautions.

Answered by Alex Feinman

Answer: Keep in Mind...

If you have a workbench with a vice, sharpening a lawnmower blade is relatively easy. The other answers have already covered the basic techniques. I don't own a bench grinder, but I have used a metal file, and a cordless drill with a grinder tip. Both methods worked pretty well for me. Rarely takes me more than 15-20 min (not counting removing and re-attaching the blade).



A few comments not covered in the other answers:


- Don't change the overall angle of the blade edge while sharpening it. The manufacturer knew what it was doing when the blade was designed.








Check out a few other tips on basic lawnmower maintenance.

Answered by msemack

Answer: The Quick Fix

Use coarse grit sandpaper to give your blade a quick sharpening. This doesn't work for big nicks and dings, but does a decent job just cleaning up the edge.


Then make sure you're mowing your lawn the right way.

Answered by mohlsen

Answer: Close might be Close Enough

There is certainly an optimal angle to sharpen your lawnmower blade, but close might be good enough. Use a dremel (or better yet, a dremel lawn mower sharpener attachment) or even a file.

If you keep an edge on your blade, the mower will run considerably smoother. And the quicker the cut, the less stress on your lawn.



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