How Sharp Should Mower Blades Be?

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To properly maintain a lawn, you really need the best tools for the job. However, even the best tools are only as good as their upkeep – something that any good worker or gardener will know to be true. 

The same goes with lawn mowers – pieces of equipment that need regular maintenance in the form of oil changes, refueling (if they are gas powered), and their blades sharpening. 

The latter is very important to achieving a neatly cut lawn. But just how sharp do they need to be, and what are the best methods to sharpen them? 

How Sharp Should They Be? 

Generally speaking, most lawn mowers should have blades that are roughly 30 to 40 degrees in terms of their angles.

This should mean that they are more than sharp enough to efficiently slash through the blades of grass, without damaging the garden, or ripping and tearing at the grass. 

One of the best ways to ensure that they remain the right angle and level of sharpness is to purchase a spare set of new blades, and compare the current set with what the new set should look like. 

If they are warped or simply not sharp enough, then it might be time to change them. 

Why Do You Need Sharp Blades? 

Even with the intended purpose of the lawn mower – that is, to cut the grass at a uniform and neat level – people seem to think that they require no upkeep, and that the labor saving nature of the product means that they too do not require any work.

However, this couldn’t be further from the truth. 

To Maintain Efficiency

The truth is that, yes, lawn mowers are a much easier way to cut grass, and really changed the whole game when they were invented all those decades ago.

However, the fact of the matter is that, for them to remain labor saving and effective, they need to be maintained. 

This means that you need to put in a little work here and there to save yourself a much larger job – or indeed a large expense – at a later date. 

To Avoid Damage

If your blades are not at the proper angle, or indeed are not sharp enough, then they could potentially cause damage to your garden – creating eyesores that are far worse than the long grass you had to begin with. 

This is because duller blades could cause rips and tears in the grass, pulling them from the soil instead of cutting them short. This could leave small craters and bald spots in your otherwise pristine lawn. 

To Avoid Injury

Sharper blades also make the job safer and more efficient. What’s more, duller blades are more likely to pick up debris while rotating, potentially causing injury if something like a pebble is picked up and thrown at people or property. 

Sharper blades mean a more fluid movement, and they are more likely to glance off of potential obstacles instead of throwing them. 

For An Even Finish

With sharp blades, you also stand the best chance of having an all over even finish – something that any gardener or green fingered homeowner strives for. 

This will avoid potential bald spots on the lawn, or indeed long strands of grass where the lawn mower missed or avoided cutting. An even finish is the best way to get a great aesthetic, and really feel as though your hard work and time has paid off.

What Are The Best Sharpening Methods? 

How Sharp Should Mower Blades Be? (1)

When it comes to sharpening your lawn mower blades, there are some methods that are worth bearing in mind. 

Sharpening Stones

Firstly, you have a sharpening stone. These are the most common way to sharpen lawn mower blades, and work by removing the dullness from the edge of the blade. 

These can be found in most hardware stores, or indeed online. 


If you have a blade sharpener that is of a suitable size, then this will be perfect for the job. It can also make light work of the process, giving you sharp blades in no time.

This process is also more controlled than other methods, and helps to get an even level of sharpness. 

You could also use an angle grinder to form the blade into a sharp edge once more. This is a more advanced method, and requires a little more knowhow – however, it can be quicker when you know what you’re doing. 

Honing Rods

You could also use honing rods and strops – although these are less commonly used than the other methods. Honing rods are diamond-coated rods which can quickly sharpen the blades of the lawn mower. 

However, these are slightly more expensive because of the diamond coating, and are less commonly found. However, these can be the easiest way to sharpen blades quickly and by hand. 

Useful Tips For Sharpening

When sharpening your lawn mower blades, there are a few things to bear in mind. 


You need to ensure the blade is properly lubricated when sharpening, otherwise you could damage the blade or create scuffs. 

Correct Sizing

You also need to make sure you are using the correct size sharpening stone or honing rod. 

Moderate Pressure

Only use moderate pressure, otherwise the blade could be damaged. 

Final Thoughts

And there we have it, everything you need to know about lawn mower blades, and how sharp they need to be to have the best results when cutting your lawn.

It’s true that the blades need to be sharp to do a good job, and can help an otherwise tiresome job become much easier on the whole. However, unless you are a frequent gardener, you might not know just how sharp they need to be. 

So if you have dull blades, or you are unsure, then be sure to refer to this guide. Something tells me you won’t be disappointed! 

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