Lawn Care

A Simple Guide on How to Sharpen Lawn Mower Blades

A great job deserves a great tool! It has been said before and I will say it here again. It doesn’t matter really what you are working on but once you’ve had the expertise, you’ll need a great tool to accompany the job. So do lawn mowers also need the same? Yes, when looking at how to sharpen lawn mower blades you will realize that the cut your lawn gets depends also on how sharp/ efficient your mower’s blades are. That is why it is very important that you have a routine maintenance for your mower’s blades by sharpening them. Here is a simple guide on sharpening lawn mower blades.


How to Sharpen Your Lawn Mower Blades

If you want to sharpen your mower’s blade there are simple steps that you should follow. Here is each and every step.

Step I. Disconnect the Power Source

Like any other sharp electronic object, a lawn mower can cause fatal injuries if it starts while you are at it. That’s why it is important to make sure that the mower is disconnected from its main power source. You should also disconnect the spark plug. Here is how you disconnect the plug.

Wear heavy gloves and eye protectors. Then remove a prominent wire on the metal mounting at the side or front of the lawnmower engine. This should ensure that the spark plug is safely out.

Step II. Turn the Mower on Its Side

To access the mower’s blades you will have to access the bottom side of the mower. This can only be done if the mower is set on the sides. Don’t turn the mower upside down. No, that can cause engine oil to spill into the carburetor and air filter. Turn it but ensure the carburetor faces up.

Modern carburetors and air filters are housed in a boxy plastic case. The case is often set on the side for most mowers. Talk to an expert to help. This includes user manual or manufacturers.

Step III. Identify the Downward Side of the Blade

Why is this important? It prevents you from reinstalling the blade upside down when you are done. If you don’t mark this side of the blade and you re-install poorly, your blade won’t be able to cut grass irrespective of how sharp it might be. Mark on the bottom side before you remove.

There are many ways to mark the downside of the blade. You could use a color mark, spray, inscriptions, marker pen, grease pen, masking tape, and many other tricks that you must know.

Step IV: Loosen the Blade’s Tightening Bolt

The bolt that secures the blade is often at the center. What this means is that if you want to unsecured it, you must unscrew the bolt. Doing this could be tricky. So immobilize the blade before unscrewing. This is a very vital part in sharpen lawn mower blades if you DIY.

To block the blade you can wedge a sturdy wooden block between the blade and the deck or you can try out a clamp if it works for you. Just counter check if your mower has reverse threads.

Step V: Clean Grass Clippings of Blade

If your blade has caught rust, is dirty, or has grass clippings on it, you may want to clean it first. This will ensure that the blade remains clean and that when you begin sharpening you will be in direct contact with the lawn mowers blades. Grime is also another thing you may want to clean out.

You can clean the blade by using a hose and mild soapy water to remove accumulated clippings, dirt, and grime. If the blade is not so dirty you can give it an old ordinary rub with the gloves.

Step VI: Sharpen your Lawn Mower’s Blade

Once you reach step V it will be time to sharpen your blade. The above steps are important and must be adhered to. There are two ways on sharpening lawn mower blades. They include the following.

Sharpening by Hand

hand-sharp-lawn mower blades

Here are the simple tips on sharpening lawn mower blades by hand. It is so simple you can DIY.

  • Clamp the blade on your workshops worktop.
  • Make sure the blade is secured – use a vice or clump.
  • Makes sure the blade sticks out over the edge of the bench.
  • Set old pieces of newspapers to trap the metallic fillings too.
  • Wear gloves and face/ eye protector/ standard face mask too.
  • Use a file to sharpen the blade. Do this by running the file along with the blade’s cutting edge.
  • Stroke from the inside part of the blade to the outside areas.
  • Do this until you see a clean shiny edge on the blades.
  • Ensure you follow the angle of the factory bevel as you sharpen.

Sharpening by Machine

lawn mower blades sharpening by machine

Unlike the manual sharpening anyone looking at sharpen lawn mower blades using a machine (bench grinders) must be very careful. Here is what you must keep in mind.

  • Once done with step V, observe safety precautions first.
  • Wear eye protectors/ gloves/ overalls and a helmet always.
  • Bench grinders can fling metallic pieces you don’t need old newspapers.
  • Move the blade back and forth along the bench grinder’s wheel.
  • You don’t have to maintain the original blade’s bevel as you work.

Step VII: Re-Install the Mowers Blade

With the above tips, your lawn mowers blades will be good to go. You can now re-install the blade. Ensure the downward side that you marked faces the underside. Secure the blade using the wooden block and refasten.

Smart Tips on How to Sharpen Lawn Mower Blades

To ensure that your mower’s blade is well sharpened, you should ensure that you keep these tips in mind.

  • Don’t sharpen your lawn mowers blade to razor sharp.
  • Make sure you wear the ideal protective gears
  • Always turn off the power and spark plug.
  • Block the blade when fastening and unfastening.
  • Clean the blades before you start the sharpening.


If you want to save more energy and time on sharpen lawn mower blades and still make sure that your lawn mower performs so efficiently you should perform long term maintenance. This includes re-sharpening your blades at least twice every mowing season, balancing the blade regularly, and replacing and blades with deep dents or cracks.

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