The side of the lawn mower blade that is up is the side that is supposed to be facing the ground. The other side of the blade, which is supposed to be facing up, is called the backside. If you were to put the blade on backwards, it would not cut as well and could cause damage to your lawn mower.
Here are a few tips to help you figure it out. First, take a look at your lawnmower blade. One side will be smooth while the other will be jagged or serrated.
The smooth side is the bottom of the blade and should be facing down when you mow. If you’re still unsure, set the blade on a level surface with the dull (or jagged) side down. Now, spin the blade slowly.
If it rotates clockwise, then that is the correct side up. Remember, when in doubt – always err on the side of caution and consult your owner’s manual!

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Hey, This is Kenny, a highly skilled machinery expert and esteemed author in the lawn mower industry. With over 10 years of experience, Kenny has become a renowned figure in the field, known for his exceptional knowledge and expertise. Today we are going to digging deep about lawn mower blade orientation and its safety precaution. Anyway, you may find more about me below:
Which Side of the Lawn Mower Blade is Up?
Before we dive into how to install a lawn mower blade, let’s first discuss which side of the blade is up. The majority of lawn mower blades are stamped with the word “up.” This indicates which side should face towards the top of the mower deck. The up-side of the blade is the one with a sharp cutting edge.
This edge is responsible for slicing through the grass blades during mowing. If you install the blade upside down, the dull side will be facing down, which will not cut the grass properly. It will instead tear and damage the grass.
Blade Orientation
The first thing to consider when it comes to blade orientation is whether you have a mulching or a non-mulching lawn mower. If you have a non-mulching mower, the blade should be installed with the sharp edge facing downwards towards the ground. This orientation helps to ensure that the grass is cut cleanly and effectively.
On the other hand, if you have a mulching lawn mower, the blade should be installed with the sharp edge facing upwards towards the deck of the mower. This orientation helps to chop up the grass clippings into smaller pieces, which can then be redistributed back into the lawn as a natural fertilizer.
Source:https://www.ehow.com/info_12320813_way-mower-blades-on.html
Does mower blade orientation matter?
Yes, mower blade orientation does matter. If you have a rotary mower, the blades rotate in a clockwise direction. This produces clean cuts on the grass and helps to prevent scalping.
If you have a reel mower, the blades are arranged in a V-shape with the cutting edge facing downwards. This also produces clean cuts on the grass and helps to prevent scalping.
How Do You Know If Your Mower Blade is Upside Down?
It’s straightforward to identify the upside down of the lawn mower’s blade. Mainly the downside of the blade is sharp and cut the grasses. So, the upside of the blade is duller than the downside of the blade.

But the main problem is with the new blade. Both sides of the new blade are shiny and sharp. In this case manufacturers always stick a label that will probably help you identify the lawn mower blade’s upside down or not.
How to identify the upside of the lawn mower’s new blade?
- The manufacturer attaches a sticker label on the upside of the new blade
- The sharp side of the blade typically faces downward. So, we can easily detect the straight side of the blade will face upward.
- Some latest lawn mowers have a great function. If you mistakenly mount the blade in the wrong way, it will not adjust properly.
Is the Right Orientation of the Blade Essential?
What happens if you put a lawn mower blade on the wrong direction?
If you put a lawn mower blade on the wrong way, these problems may arise:
- Ripped Grass- If you mount the blade in the wrong orientation by any mistake, you will not get the crisp and sharp result after mowing the grass. Instead of it, you will see grasses are ripped positively, and that’s very noticeable and unpleasant.
- Ruined Blade – Regular blades have sharp side edges. It spins in the right direction and cuts the grass perfectly. But the wrong orientation of the lawn mower blade can destroy the blade. But also, you will need to change the blade after one time of use.
- Damaged Mower – Now, this is the biggest problem if you will assemble the blade in the wrong position. Suppose you are mowing the grasses, and there are some small stones on the surface.
Then the blade is spinning backward because of the blade’s wrong orientation. It will start to toss those stones inside your lawn mower, and you will face the worst situation at that time.
How to Install a Lawn Mower Blade?
Now that we’ve established which side of the lawn mower blade is up and why it matters, let’s discuss how to install the blade correctly.
Step 1: Preparation
Firstly, make sure that the mower is turned off and the spark plug wire is disconnected. Then, turn the mower on its side with the carburetor facing up. Secure the blade with a block of wood to prevent it from spinning.
Step 2: Remove the Old Blade
Using a wrench or socket, remove the bolt that secures the blade to the mower deck. Carefully remove the old blade and place it aside.
Step 3: Install the New Blade
Now, align the new blade with the spindle shaft, ensuring that the word “up” is facing the top of the mower deck. Replace the bolt and tighten it securely using the wrench or socket. Do not over-tighten the bolt, as this can damage the blade.
Step 4: Check the Blade
Once the blade is installed, check that it’s straight and level. A blade that’s not level will not cut the grass evenly, resulting in an unattractive lawn. To check the blade’s level, place a block of wood under the blade and check that it’s level on both sides.
Safety Precaution
Lawn mowers are essential tools for maintaining a healthy lawn. However, they can be dangerous if not used correctly. Here are some essential tips to keep in mind when operating a lawn mower:
Blade Direction: The sharp edge of the blade should be facing outwards, away from the lawn mower deck. This ensures proper cutting and safety.
Clothing and Safety Gear: Always wear appropriate clothing and safety gear when operating a lawn mower. This includes closed-toe shoes, long pants, and safety goggles.
Clear the Area: Before starting the lawn mower, clear the area of any objects that could become projectiles. This includes toys, sticks, and rocks.
Mowing on Slopes: When mowing on slopes, be extra cautious. Never mow across the slope, and always mow up and down. If the slope is too steep, consider using a push mower instead.
Turn Off the Engine: Before performing any maintenance on the lawn mower, turn off the engine and disconnect the spark plug. This will prevent the mower from accidentally starting and causing injury.
Most common questions about mower blade orientation
How Do You Tell the Top And Bottom of a Lawn Mower Blade?
There is usually a small notch in one end of the blade. This corresponds to a raised section on the spindle (the metal bar that the blade mounts on).
The spindle is usually slightly longer at this end, so that when the blade is mounted with the notch towards the ground, the cutting edge of the blade will be lower than at the other end of the blade. Some blades are made with a curved shape, so that they can be installed either way and still cut effectively in both directions.
Which is the Cutting Side of a Mower Blade?
It might seem like it would be obvious – the sharpened edge that does the chopping, of course! – but surprisingly, that’s not always the case.
Some mower blades are designed so that both sides are sharpened and can be used for cutting. Others have one side that is sharpened and one side that is blunt; these types of blades are typically known as “reversible” blades. And still others have only one sharpened side; these are known as “non-reversible” blades.
What Happens If You Put Lawn Mower Blades on Upside down?
If you put lawn mower blades on upside down, they will cut the grass less effectively because the blade will not be able to make contact with the ground properly. The lawn mower may also vibrate more and create more noise than usual.
Which Way Do Mower Blades Go on John Deere?
Which way the John Deere mower blades go on- The first thing you need to do is locate the blade control lever. This is usually located near the front of the deck on the right hand side.
Once you have found this, you need to identify which direction the arrow is pointing. The arrow should be pointing towards the ground when the engine is off. If it is not, then you need to adjust it so that it is.
Now that you know which way the arrow is pointing, you can start your engine and engage the blade control lever. Make sure that your PTO switch is in the “on” position as well. You should now see that the blade spins in a clockwise direction when viewed from above.
If it does not, then you have installed your blades incorrectly and will need to reverse them. Congratulations! You have now successfully learned how to install John Deere mower blades correctly!
Which Way Do Mulching Blades Go on a Riding Mower?
For most models, the blades should be mounted so that they rotate in a clockwise direction. This will ensure that the grass is cut in a manner that produces finely chopped clippings that can quickly decompose and provide nutrients for your lawn. There are a few exceptions to this rule, however.
Some newer models of riding mowers have been designed so that the blades rotate in a counterclockwise direction.
Husqvarna Mower Blade Position
The Husqvarna has a rear-discharge deck that puts the blades closer to the ground, which results in a better cut. You can also adjust the blade position to get different cutting heights. This feature allows you to tailor your mowing experience to your lawn’s needs.
How Tight Should Lawn Mower Blades Be?
The answer may surprise you – they actually should be quite loose. This is because when the blades are too tight, they can cause the engine to overheat and potentially break down.
Therefore, it’s best to err on the side of caution and keep your blades loose. Of course, this isn’t to say that you shouldn’t tighten your blades at all – just don’t go overboard.
Which way do the blades go on a zero turn mower?
For John Deere and Cub Cadet, the blade goes with the curved side facing down. For Husqvarna, it is reversed with the flat side down.
Final words
Installing a lawn mower blade may seem like a simple task, but it’s essential to do it correctly. Installing the blade upside down can damage your lawn, increase fuel consumption, and cause permanent damage to your mower. Remember to always check which side of the blade is up before installing it and ensure that it’s installed correctly.
By following the steps outlined in this article, you’ll have a healthy, green lawn in no time.