To Sharpen or Replace Mower Blades?

27 July 2023

One of, if not the most important steps in servicing your lawn mower, is making sure your mower blades are sharp and in good condition.

Blunt mower blades will rip at your grass, which not only looks bad, but isn’t good for the health of your lawn.

How do I know if they should be sharpened or replaced?

In order to determine whether they should be sharpened or replaced you need to inspect their current condition. To do so, tilt your lawn mower up with the front wheels pointing upwards and the handle flat to the ground or bench. This will ensure no oil flows where it shouldn’t, causing you even bigger problems.

If the blades have any cracks, bends, extremely thin blades or even holes in the blades fin – then your blades need to be replaced.

If there is still plenty of meat left on your blades and they are in their correct shape, they may simply need to be sharpened.

For most people, the easiest fix is to have your mower blades looked at by a professional. If you are not confident or short on time, your best option is to drop your lawn mower off at your local mower shop. The experts will be able to give the whole unit a once-over. It can be a good idea to undertake a mower service every 12 months or so, leaving your mower ready to go when you need it during the warmer months.

If your blades just need a sharpen or you are confident in replacing them yourself, here’s how to go about it for most standard lawn mowers…

How to replace your mower blades


Socket Wrench and sockets

Allen Key Set

New blades kit

Step 1. Disconnect your spark plug lead from your spark plug.

Step 2. Tilt mower upwards, front wheels in the air and handle to the bench or ground as mentioned above.

Step 3. Using the wrench, you can remove the main bolt securing the base plate to the cutting deck. Then remove the blade bolts. Or you can remove the blade bolts while the plate is still attached to the mower. The blade bolt head may require the use of an Allen key to stop them from spinning while you remove the nut.

Step 4. Remove old blades and put your new blades in place on the bottom of the base plate. The base plate will spin anti-clockwise so make sure the cutting edge of the new blades is directed towards the direction they will spin. A mower blade replacement kit will come with a plastic washer. This goes onto the bolt on the bottom of the base plate. It will also come with a steel washer for the underside and the nut to tighten it in place.

If you are going to sharpen your blades, make sure you are very careful as to only take the slightest amount off the blade and keep it even, so you don’t throw the blades out of balance.

Step 5. Put your new washer and bolts on and secure them in place tightly. The blades should still move if a decent amount of force is applied. This will enable them to absorb a hit from a large obstacle or rock avoiding damage to other components.


As always, if you have any more questions please don’t hesitate to contact us for free expert advice on 1800ALLTURF (1800255873) or 07 5543 8304.


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