A blunt lawn mower blade isn’t going to provide you with the cutting performance you require from your lawn mower, regardless of how powerful it is. Instead, you will find yourself left with an uneven, patchy lawn that looks as if it’s been mown by hand with garden shears.

Keeping your lawn mower blade sharp will maintain grass cutting efficiency and provide a cleaner finish to your lawn. A sharp cutting blade will also place less stress on your lawnmower and will prevent undesirable jamming during use. Sharpening your lawn mower blade may not seem like an important task but a sharp cutting blade will vastly improve the condition and appearance of your lawn.

We recommend sharpening this metal blade at least twice every mowing season.

Preparing Your Lawn Mower

Sharpening mower blades is an easy job, but there are a few safety precautions you should follow to prevent personal injury and damage to your mower.

The most important step is to prevent your mower from being accidentally started when the blade is exposed. If you have a petrol mower, you will need to remove the spark plug wire. We’ve provided instructions on how to complete this process in our lawn mower servicing guide.

If you have an electric mower, be sure to remove the battery if a cordless mower or unplug it from the mains.

If your blade is beyond repair and visibly damaged, we wouldn’t recommend trying to sharpen it. Instead, we recommend replacing it with a new cutting blade. They can be sourced directly from the manufacturer or any good DIY retailer whether you own a hover mower or petrol mower.

Hand push lawn mowers use a rotating cylinder to cut grass which feature on average five individual cutting blades. There are specific kits you can buy to sharpen this type of mower blade or you can visit a mower repair shop instead.

A Guide to Sharpening Your Lawn Mower Blade

  1. Before removing the blade from the lawn mower, mark the bottom of the blade with Tipp-Ex or paint to avoid reinstalling it the wrong way around when putting it back together.
  2. Loosen the holding nut with a socket or spanner and carefully remove the blade.
  3. Clean the blade with warm soapy water and dry it thoroughly with a clean cloth. If there are signs of corrosion or rust on the blade, remove them with steel wool or a brillo pad.
  4. Secure the blade in a vice or other suitable clamp and use a metal file to ‘brush’ the cutting edge of the blade. You can also use a drill or purpose made tool with a grinding attachment on it. Make sure to follow the angle of the bevelled edge of the blade while sharpening.
  5. Once the blade has been sharpened, check its overall balance from the centre point. If it is out of balance, file a small amount of material from the heavier side until this imbalance is rectified.
  6. Replace the blade by following the removal procedure in reverse, making sure to firmly tighten it once in place.
  7. Replace the spark plug wire or plug the power socket back in and start the mower to check for smooth operation.
Sharpening Mower Blade

Final Verdict

Keeping your lawn mower blade in good condition is just as important as cleaning the mower itself and servicing the engine if powered by petrol.

Regularly examine the condition of your mower blade and be sure to either sharpen or replace it when necessary.