There’s nothing like that fresh factory smell when you take delivery of your new tractor. Of course, the first thing you want to do is take it out for a spin, only to notice that the blades look a bit dull.
You then wonder: does new lawn mower blade need to be sharpened? You would expect that, but experiences don’t always match expectations.
This article will explore that topic as well as how to sharpen mower blades, the frequency and how to tell if the mower blade is sharp.
Does New Lawn Mower Blade Need to be Sharpened?
No, you should not sharpen new mower blades. The manufacturing process produces blades that are already sharp and ready for use. Sharpening can reduce the life of a blade by blunting its edges over time, making it less efficient at cutting grass. It’s recommended only to sharpen a blade if it becomes damaged or wears out.
Do You Need to Sharpen New Lawn Mower Blades?
No, you don’t need to sharpen new lawnmower blades. When a lawn mower or lawn tractor comes from the factory, the blades come ready to cut according to the manufacturer’s specifications.
The same is true if you buy new lawnmower blades to replace your old ones. The reason some people think they need to be sharpened is that replacement blades come looking blunt.
That’s because they have a powder-coated paint finish that feels dull. However, don’t let the dull appearance deceive you – those blades are ready for work.
See: Are bush hog blades supposed to be loose?
Do New Painted Mower Blades Need to be Sharpened?
No, they don’t. Replacement blades come with a coat of paint for three reasons.
1. To protect you
Chances are high that you will try to handle the blade without protective gloves because, well, people are stubborn! If that happens, the manufacturer doesn’t want you suing them.
2. To protect the blades from impact
It’s almost a rite of passage to drop new lawnmower blades when trying to fit them in. When this happens, you’ll be glad to know that the sharp edge has been protected from abrasions and impact.
Of course, some of this paint will come off when it falls, but it’s still not a problem.
3. To protect the blades from rust
Who knows how long lawnmower blades sit on the shelf before they get sold? Well, nobody cares as long as they come ready to do their job.
Needless to say, rusty lawnmower blades are useless to the owner and a waste of money for the manufacturer to issue a refund. So, what happens after you install the blades?
As you mow, the powder coat will gradually chip away, revealing the sharp underbelly. It usually takes about half an hour for this breaking-in phase to occur.
What Happens if You Sharpen New Lawn Mower Blades?
Unfortunately, there is such a thing as having too sharp blades. Trying to sharpen new lawnmower blades beyond what the manufacturer has done will compromise the integrity of the blades.
Instead of making it sharper, you’ll only be making the edge so thin that it begins to crack and chip away even before it has made any contact with grass.
Sharpening new mower blades will also affect their balance, which opens another can of worms.
You would need to rebalance the mower blade before using it, or it will affect the spindle and the engine.
By compromising the integrity and balance, you have shortened the lifespan of your brand-new mower blade. So, when you get it out of the box, install it and start using it.
Read: Sharpening edger blades
How Often Should I Sharpen Lawn Mower Blades?
How often you should sharpen your lawn mower blade will depend on your manufacturer. However, the general rule is lawn mower blades need to be sharpened every 25 hours.
For residential lawnmowers, that could mean just once a year at the beginning of summer.
For commercial lawnmowers, this could mean once a week, especially if you mow a few acres multiple times a week.
If you mow a lawn with many stones, you might need to sharpen it more often. So, the soft rule is every 25 hours, and the hard rule is to sharpen your lawn mower blade whenever it gets dull.
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How Do I Know When a Lawn Mower Blade Needs to be Sharpened?
When you mow a lawn with a lot of obstacles or tough grass, you often won’t need to wait 25 hours before sharpening the blades.
You should sharpen the blades when the leading edge has indents. You should also check to make sure it still has a bevel.
Wear safety gloves before inspecting the surface of the blade. If you feel the dents, even if you can’t see them, you must work on your mower blade.
Can I Use a Dull Mower Blade?
Many people forget to sharpen their mower blades or don’t think they need to because it still cuts.
The problem is a dull mower blade puts an unnecessary strain on the lawn mower, will slow you down as a user, and cost you more money.
The main problem with mowing with dull blades is that you won’t get a clean cut. The blade will pull the grass instead of cutting it, leaving a ragged edge.
The rough cut on the grass will start to turn brown and will leave the grass vulnerable to disease.
Dull mower blades need to work harder to cut grass, meaning more energy is being used by the lawn mower, which affects the battery, the engine, and the fuel system.
A dull lawn mower blade also affects airflow, which can affect the mower deck by forcing the parts to work counter to design.
In summary, unless you want to replant your lawn or buy a new lawn mower, it is best to keep the blades sharp at all times or replace them.
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How Often Should I Replace Dull Lawn Mower Blades?
Lawn mower blades typically need to be replaced every 200 hours. Considering the average American will spend 384 hours mowing in their entire lifetime, this would suggest you only need to replace blades once.
Some experts recommend replacing mower blades once a year. However, if you sharpen your blades every season, they can last about four years before they need to be replaced.
The 200-hour rule is better applied to professional landscapers, amounting to once a season.
However, Oregon Gator blades last considerably longer and can go 400 hours before needing to be replaced.
Do I Need to Remove Mower Blades Before Sharpening?
No, you do not need to remove the mower blade before sharpening. Many tools, such as palm grinders and power drills, can sharpen the blade while it’s still on the mower.
However, it does pose several challenges, such as not being able to ensure the right balance and there is no vise to keep the blade in place while you work.
As much as it may seem like this will save you time, you will still need to remove the blade to check the balance, so we don’t recommend it.
How to Sharpen Dull Lawn Mower Blades
There are different ways to sharpen a lawn mower blade. The easiest way is to outsource it to a professional, making it the most expensive.
Fortunately, tuning your blades is pretty simple, so most manufacturers include a step-by-step guide in the manual.
Here is a general method for any mower blade to return its razor edge.
Tools you’ll need to sharpen a lawnmower blade
- Protective gloves
- Safety goggles
- Plank
- Ear muffs/protection
- Wrench
- Microfiber cloth
- Sharpening tool
- Metal file
- Drill-powered sharpening stone
- Bench grinder
- Vise
- Blade balancer
Steps to sharpen your lawnmower blade
Step 1: Stop the power flow
Before you begin this step, you need to wear your safety gloves and safety goggles. Next, you need to disconnect the spark plug wire to prevent any ghastly accidents.
A spark plug could misfire even with the engine off, causing the blade to spin incorrectly. If it is an electric mower, remove the battery or unplug it.
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Step 2: Tilt the lawn mower
Depending on who you ask, they might tell you to drain the gas tank and empty the engine oil before removing the mower blade.
However, if you tilt the lawn mower on its back – not side – the gas and oil will remain intact and not flow into the air filter.
You will also be keeping the carburetor upright. However, this only works if your lawn mower has a standard configuration. Consult the manual on how best to angle your mower.
Related: Does regular gas go in a lawn mower?
Step 4: Unscrew the blade
Before you take off the blade, it helps to mark it so you know which side should be facing down when you put it back together. A permanent marker or a bit of paint should suffice.
To remove the blade, some people recommend you put a plank to wedge it in place. However, if you’re not careful, the plank could bend the blade.
Lawnmower blades aren’t so sharp that they can cut you, so it is better to hold the blade (wearing safety gloves, of course) while you unscrew it.
Ensure you have the right size socket, or you can round them off very easily. Once the blade is off, keep the nut or bolt safe. You may clean the mower deck now or wait before you reassemble it.
Step 5: Clean the blade
Get your microfibre cloth and gently clean the surface of the mower blade. This will help eliminate any dirt that might impede your work, but more importantly, it’ll help you better identify any dents and bruises.
If you notice that the lawnmower blade is cracked, get rid of it and buy a new mower blade. Otherwise, move on to the next step.
Step 6: Sharpen the blade
There are many ways to sharpen a blade, but we’ll discuss the top three.
Metal file
Sometimes, not all the time, old school is the best school. The first thing you need to do is clamp the mower blade with a vise, ensuring that the sharp edge is facing upwards.
Next, place the file on the bezel of the blade and file in one direction only, downstroke away from the blade.
Ensure that you place the file on the exact slope of the dull blade so you don’t change the cutting angle.
You should keep filing until you’ve gotten all the nicks out, which may take a few minutes. Once it’s smooth, flip the blade over to the other side.
Using a metal file may not be the fastest method, but it is the best because it protects the integrity of the mower blade. However, if you don’t have the patience, try option 2.
Sharpening stone/blade sharpener
If you have a power drill, you can palace a sharpening stone on it. It is a circular stone that sits on a tough bit of plastic, which provides the right angle for sharpening.
Place the plastic guide on the backside and run the drill across the edge. Unlike with a metal file, you can go in both directions.
Bench grinder
An electric bench grinder is the quickest way to sharpen a mower blade. Simply turn it on, and press the dull blade against it sweepingly. You must wear ear muffs for this, but it only lasts a few seconds per side.
Step 7: Check the balance
Sharpening will shave metal off the dull blade, so you must carefully remove the same amount from both sides. You should place the mower blade on a blade balancer to make sure.
If one side of the blade drops, you have an unbalanced mower blade, so you need to shave it off some more.
Another way to check the balance is to hang the lawnmower blade on a nail in the wall. The same thing will happen. There will be very little movement if the blade is balanced.
Step 8: Put the blade back
You may decide to give the blade one final polish with the cloth to get rid of any lingering metal shavings before you reassemble it.
Ensure you have screwed it the right way up and it’s tight before you tip the lawnmower back down.
Read: What grit flap disc for sharpening mower blades?
FAQs
Do mower blades come sharpened?
Yes, brand new mower blades come pre-sharpened from the manufacturer. However, not all do, so it’s essential to check the product details or packaging. If they are not pre-sharpened, you may need to sharpen them before use to ensure efficient and clean lawn-cutting.
When to sharpen the mower blade?
Sharpen your mower blade at least once every mowing season or after approximately 25 hours of use. However, inspect the blade regularly for signs of dullness or damage. If you notice uneven cuts, brown tips on the grass, or an increased mowing effort, it’s time to sharpen the blade.
Should you remove the paint from the new mower blades?
You should not remove the paint from new lawn mower blades. The paint prevents rusting and other forms of corrosion and does not negatively impact the blades’ performance. After a few mowing sessions, the paint will naturally wear off, and the blades will function optimally while protected from rusting.
New lawn mower blade seems dull
Brand-new lawn mower blades are designed to be used as they are. Contrary to being dull, they cut at a slightly slower pace and have excellent durability, resulting in a longer lifespan.
Using them without immediate sharpening ensures the right balance for optimal performance. Over time, as they naturally wear, sharpening can be considered to maintain their cutting efficiency.
How sharp do lawn mower blades need to be?
Lawn mower blades need to be sharpened to a fine edge for optimal performance. However, it is essential to strike a balance between sharpness and durability.
Overly sharp blades can dull quickly, while too dull blades may not cut effectively. Aim for a sharpness level that ensures a clean and even cut without compromising the blades’ longevity. Professional sharpening services can help achieve the right balance.
Final verdict – do you need to sharpen new mower blades?
Taking care of a lawn is hard work, but it is a lot easier with a new blade. Perhaps what is even better is knowing that a brand-new lawnmower blade does not need to be sharpened.
Now that you’ve learned how to sharpen a lawnmower blade, perhaps you won’t be so quick to get rid of a dull lawnmower blade.
However, before you sharpen the dull blade, you need to know where the carburetor on a lawn mower is located.