Which Way Should Blade Face On Lawn Mower?

The right way to face the lawn mower blades can be confusing, especially for beginners. Some specific sides should be facing toward the ground and some towards the upside. If you want to know the right direction of the mower blades, this is the right place.

The sharp edges of the lawn mower blade will spin in the lawn mower’s rotation direction, bending towards the grass at times and having a taper that faces the sky. Pull the starter to see the rotation direction. The dull edge will be bent and face toward the mower deck. 

There are several other things to know about the blade’s direction. Otherwise, you will face difficulties while mowing. Please keep reading to learn the steps to install the blade in the right direction and the results of putting them in the wrong direction. 

Decoding the different sides of the mower blade: Which sides are Up and Down?

The mower blade has two sides that must be faced in two different directions. 

When you fix the mower blade, you need to understand these two sides so that they face in the right direction.

One side of the blade is a cutting edge. 

It is sharp and used to cut grass. 

This side should face towards the grass to cut them down. 

On the contrary, the dull side has a smooth surface and should go up when the mower is upright. 

Sometimes, stamps on the blade guide you on which side of the mower does what job and which side should be faced Up or Down.

The mulching blades in the mowers face the same way as the rotation blades. 

These blades are slightly curved than the other blades because they provide better mulching and lawn cutting. 

The next part clearly explains the blade orientations in the mowers. 

Blade orientation: Understanding the correct direction for the lawn mower blades

While changing the mower blades, you must know their orientation and the different sides. 

As I said earlier, the sharp part should always stay toward the grass. 

The blade’s dull side should stay bent and face toward the mower deck. 

The blades cut and throw the grass clippings outwards from the mowing direction, away from already mowed areas. 

The blade must also spin in the mowing direction. 

It must be secured tightly and checked regularly for wear and tear or damage to efficient functionality. 

For a lawn mower that is not bent or angled correctly, you need to figure out the blade’s spinning direction in the mower. 

If your lawn mower needs to be cranked to start, pull the crank and notice the blade’s movement direction. 

The sharp-edged side of the mower needs to spin in the direction of rotation to cut the grass efficiently. 

There are two different types of mower blades:

• The side discharge or the rotation blade 
• The mulching blades 

The discharge blades cut the grass and discharge the clippings in the side of the mower deck. 

Here the blade facing is regular; the cutting edge towards the grass downside, and the dull end towards the sky.

But the mulching blades cut the grass, chop them finely, and redistribute these clippings over the lawn as mulching; that’s why the name. 

The orientation is the same but can vary depending on the mower type.

If the rotation blades spin clockwise when you see from the top, the same is for the mulching blades. 

In most cases, the curved edges of the mower blade face towards the deck and the flat side upwards. But it is better to consult with the manufacturer. 

Blade placement demystified: A clear understanding of which way the mower should face

The above two sections explain that the sharp edge should face down toward the grass, and the dull side should face toward the sky.

But how do you understand whether you maintain the mower’s correct orientation? 

Beginners need more help understanding or recognizing which side of the blade should be faced in which way. 

So, here are a few signs that help you know which side the blade should face: 

Type of blade

When you position the blades, understanding the blade type to know about the blade’s orientation is essential. 

I have already shared that there are two blades – the discharge blades and the mulching blades. 

The discharge blades cut the grass and deposit the clippings into the bag or side of the lawn. 

These blades have a slightly curved shape.

On the contrary, the mulching blades cut the grass into small pieces, leaving them over the lawn as mulch. 

These blades are curved with serrated edges. 

The orientation for both blades is the same. 

The blades’ sharp edges should be towards the grass, and the dull side should be upwards.

But, sometimes, it is more challenging to understand than it seems, especially for beginners. 

Let’s learn the other ways of identifying the directions of the blade sides.

Find the CUT GRASS stamp

The lawn mower blades cannot be interchanged with anything else. 

Most mower blades contain a sticker or stamp telling you which sides the blade should face. 

Some lawn mower models have engraved or machine-printed words on the blade telling in which direction it should be and which side of the blade should be placed in what direction. 

However, some models do not have such things, or the words can get covered by rust over time. 

So, when you open the blades, know which side is placed in what direction. 

You can also put your own stickers on those sides to remember the correct blade orientation. 

Find the cutting edge on the mower blade

It is one of the easiest and most reliable methods to understand blade orientation. 

The cutting edge should be sharper than the dull side of the blade. 

This part is used to cut the grass. 

As explained earlier, the cutting edge must always face the grass as it will be chopping and shaping them.

But rotation blades have tapers at their end, which should be pointed towards the sky. 

It is the right way for the blade to face. 

Always be cautious while handling the mower blade to avoid injuring yourself. 

The cutting edges are not interchangeable. 

If the blade you have does not have the exact dimensions in the center hole and the length of the instrument, do not use it for the lawn mower.

Using the wrong type of blade can create new unknown issues. 

Find the wings

The blunt side of the blade stays down towards the grass to chop them. 

If you cannot identify the blunt side, check for the wings. 

The dull sides of the blade have very slightly raised edges, resembling tiny wings. 

These wings provide air vacuum and lift the grass blades. 

Once the air pressure lifts the blades vertically, the cutting edge can quickly chop off the grass. 

Sometimes, the wings on the upper side are difficult to spot. 

You can feel them with your fingers along the edge. 

Using your tactile sensation, gauge which sides are up and down.

Perform wobble test

This method can help you find the correct blade orientation after adjusting or replacing them. 

Hold the mower blade with one hand and the deck with the other hand.

Tug at your blade and pull it down. 

If the blade faces the right side, it should not wobble.

But if the blade is in the wrong direction, tighten the securing bolts with a wrench and make sure it is on the blade shaft. 

Reel mower

The reel type of push mower is an exception because its cutting blades have no ups and downs.

The mowing blades of these lawnmowers are arranged in a cylindrical manner. They roll like a wheel when chopping the grass. 

The edges of these mower blades are equally sharp. 

So, there are no upsides or downsides to the blades. 

You can face the blade on any side of the mower. 

Blade direction Dos and Don’ts: Essential guidelines for installing lawn mower blades

You should not install the blades upside down, i.e., placing the cutting edge up and the dull side downwards towards the grass. 

The mower blades are designed to work with a particular orientation in a specific direction so that the machine performs well and cuts the grass clearly and efficiently. 

If you alter the orientation, there can arise other issues.

Dos

The Dos of the mower blade include the following:

• Position them in the direction of the mowing. 
• Put the sharp edges on the downside towards the grass to cut them. 
• If there are tapers in the blade ends, it should point towards the sky.
• The dull side should face upwards towards the sky. 
• You can line up the lawn mower blades to ensure that the mower is evenly cutting the grass, keeping the lawn neat and clean, and preventing the blades from cutting too deep and damaging the grass. 

Don’ts: Installing the blade upside down

In the Don’ts of the lawn mower blades, most beginners make one common mistake: installing the blade upside face. 

As a result, the cutting edges face the sky, and the dull edges face the grass. 

Though this setting is found in some new mower models, the opposite is safer and ideal for mowing. 

When you put the mower upside down, you have the following problems:

• The grass can be cut unevenly with upside-down blades and take much longer to mow.
• The blades will damage if you mow them in the upside-down direction. They will become dull sooner than expected and lead to uneven cuts.
• The blades can wear out faster because the dull side that cuts the grass becomes dull, leading to more frequent replacement.
• With the upside-down orientation, the mower will damage faster. The blades wobble too much, hit the mower’s metal, and damage the interior of the mower. You will hear clanging sounds from the mower, stop mowing and check the blades once.
• The blades can get damaged and break if you install them upside down. 
• The wings of the blades can bump with stuff on the ground, put extra pressure on the crankshaft, and lead to a broken crankshaft. 

Guidelines to replace the mower blades

As a beginner, I never thought about the frequency of changing the mower blades. 

The mowers must be typically changed after 200 hours of usage and even more, which is 1-2 times yearly. 

To replace the mower, you will need:

• Cut-resistant gloves
• Wrench
• New mower blade that fits your mower model. 

Here are the steps to install new mower blades:

1. Gather the materials you need. Buy a blade that suits your mower model. Otherwise, the blade won’t get installed properly.
2. Lower the mower on the ground to get hold of the blades. 
3. Remove all the leftover grasses from the mower deck.
4. Use a wrench to remove the bolts holding the blades in place and keep the bolts aside. 
5. Remove the old blade and take the new blades.
6. First, check and determine which side should be faced in which direction. Place the cutting edge downwards to the grass and the dull side upwards. 
7. Place the blade onto the mower, collect the bolts, and tighten the blade in place. 
8. Try the wobble method to ensure they are tightly secured and not moving. 
9. Your mower is ready for use. 
10. Throw away the old blades. 

Can I bend the blade a little while installing it?

You can bend the mower blade slightly while mowing for effective grass cutting. But you need to be careful with this. 

Wear protective gear while doing it and protective goggles if the blade snaps back. 

Hold the blade with a vise or pliers and bend it back with a hammer or a tool used for bending it. 

Please do not hit the blade too hard, or you have to replace it.

Once the blade is bent, check it properly to ensure the holes line up well, as it needs to get reattached to the mower in the bent position. 

When you bend the blade, the mower will vibrate a bit because it creates an imbalance when it spins, causing the mower to vibrate. 

If there is too much imbalance, the vibration can be higher than usual. 

It will further overheat the components, like the engine, to vibrate and overheat, leading to mower damage and other internal components. 

If you do not fix the blade’s balance, it can also give you uneven cuts, leaving patches and stripes. 

So, if you are bending the blade, balance it well and get the holes lined up to attach it correctly to the mower. 

Cutting with precision: How to sharpen the mower blades?

To cut the grasses with precision, you must keep the mower blades sharpened and install them in the correct directions. 

Sharpening the blades can save you a lot of money. 

You do not have to buy the mower blades frequently. 

But the work requires experience and knowledge, and it needs time.

You can use a blade for a long time as long as you sharpen them regularly after every mowing session, every 25 hours of usage, to be precise.

Tools needed:

• Flat metal file, drill-powered blade sharpener, or disc grinder
• A vice that holds the blade in place
• Blade balancer 
• Rags
• Wire brush
• Safety glasses
• Work gloves

Here are the steps to sharpen the mower blades:

1. Put on your safety glasses and gloves. 
2. Clean the blades with rags and remove the dirt and debris. Use a wire brush if needed. 
3. Keep the blade in the vice and start sharpening the blade with the metal file. 
4. Push the file at a 45-degree angle in one direction along the blade for sharpening. Avoid sawing motion. 
5. Once you have sharpened one side and removed all the rough spots and uneven edges, flip and sharpen the other side. 
6. Grind the edges very well to sharpen them. Make sure not to over-sharpen, as that will break the blade edges. 
7. Make sure you balance the blade on both sides after sharpening. 
8. Reinstall it in the mower. Put the cutting edge down on the grass’s side and the dull side upwards. 

If you use the drill-powered method for sharpening:

1. Power the drill with the blade sharpener attached to it. 
2. Put the sharpener’s guide along the blade’s flat part, keeping the cutting edge slot into the slope. 
3. Move the sharpener up and down at the blade’s length.
4. Once you do it with one side, flip and repeat for the other. 

To sharpen the mower blades with an angle grinder or bench grinder:

1. Hold the grinder perpendicular to the blade edge. 
2. Run the grinder along the blade’s length to level out the rough spots and nicks. 
3. Keep moving the grinder to remove some metal to produce a clean sharpness. 
4. Do it with the other side as well. 

Final Thought

Understanding which way to face the mower blade in the lawn mower is easy. The cutting edge must always stay down towards the grass to chop them, and the dull side should be upwards facing the sky. As beginners, it can be slightly tricky to understand. Still, there are a few ways, for example, looking for the stamp marks, finding the sharp side, locating the wing side, or performing a wobble test. 

Also, keep in mind the moving direction. Install the blade correctly so it rotates in the mowing direction. There are 2 types of blades – discharge and mulching blades. Both the blades’ sharp sides faced the grass. But sometimes, the mulching blade’s orientation differs slightly from the rotation blade. In that case, you must ask the manufacturer or consult the manual for the correct direction. Do not install the blades upside down. 

That can damage the blades, cut the grass unevenly, and even damage the mower. Additionally, wrongly installed blades can run irregularly and harm you. So it is better to install them correctly. If the orientation seems different, consult the manual. However, reel mower blades do not have such orientations. Both sides are similarly sharp, for which they do not have such things right up and down or cutting or dull edges. 

Reference: Lawn Mower Blade