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A dull lawn mower blade is one of your worst enemies as a gardener. It will tug and tear at the grass, weakening the lawn and promoting fungal growth and disease. You simply won’t be able to get a quality cut with a blunt blade.
With a sharp blade on the other hand, you will get a clean, fast cut, with better results in less time. The grass will be kept in tip top condition
If your mower has dents in the blade, or nicks. If the grass height is uneven, and blades of grass look frayed or torn, rather than cleanly cut, you probably need to sharper your mower blades.
Over time, all blades will become dull, so it is worth sharpening the blade regularly to help maintain the mower and keep a healthy lawn. Typically most regular mowers will sharpen the blade twice every mowing season.
Here’s the best way to do it.
NOTE: THIS ONLY APPLIES TO ROTARY MOWERS! NOT RIDE-ON MOWERS OR CYLINDER MOWERS.
Step 1. Remove the blade
The first step is to remove the blade.Be very careful while doing so as this is potentially sharp and heavy. Donning gloves might be a good idea. You will usually find that the blade is held on with a nut. This will be very tight, and you are likely to need a long handle wrench or spanner to loosen it. Have some oil to hand to squirt in case it doesn’t loosen very easily.
You may need to remove rust with WD 40 and wire wool before it can be sharpened, or if badly damaged it may need replacing.
If you have a petrol mower, be careful tipping up the fuel tank when removing the blade, and if you have an electric mower, make sure its unplugged.
Step 2. Sharpen the blade
With the blade in your hand, take a hand file and get to work running the file along the blade. Grinders will also do the same job much faster, with less finesse.
Sharpen from the top side of the cutting edge, and file only on the push stroke of the file.
Check this video if you’re not sure.
Also bear in mind that the mower blade doesn’t need to be razor sharp. As sharp as a butter knife will do the trick.
If you don’t have a file or a grinder, you can try using coarse grit sandpaper.
Or you can get one of these to attach to your drill:
- Precise and Sharp Cuts: Re-sharpens metal rotary mower blades quickly to the correct angle, restoring top cutting action in just minutes. There is also no need to remove the blade from the mower.
- Multi-Purpose: Re-edges and re-sharpens spades, hoes, lawn-edgers, axes and other garden tools and accessories, making them much easier and safer to use.
- Sharp as New: Reversible Corundum grinding wheel gives 10 mower blade resharpenings. Lasting for many seasons.
- Universal Fit: This sharpener fits any power drill, both corded and cordless, to get you working in no time.
- Maintain Your Lawn: Sharp blades give a clean cut and are healthier for the grass and safer for you to work with.
Step 3. Replace the blade
Before replacing the blade, check it is balanced by pivoting it on a nail. f not balanced, try removing some material from the heavier side, but be careful of the cutting edge. Then reattach the blade to the mower with the nut. Nice and tight. You don’t want it swinging off and damaging yourself while mowing.
Mower blade sharpening FAQ
Are mower blades universal?
Mower blades are not typically universal and interchangeable. They are usually mower specific, but some blades will of course fit other mowers.
Can mower blades be too sharp?
Yes, mower blades that are too sharp get nicked easily and become dull faster, meaning they must be sharpened more regularly.
Where can I get mower blades sharpened?
Garden tool sharpening tends to be offered by small local companies.