Which Side Of The Lawn Mower Blade Is Up

Which Side Of The Lawn Mower Blade Is Up?

Lawnmowers are pretty self-explanatory, but figuring out how to properly operate them? Now that can be the tricky part, especially for first-timers. 

For your lawnmower to perform in tip-top shape and ensure that you get the job done, you first need to install your blades properly.

Installing a lawnmower blade incorrectly can sometimes result in it not even cutting the grass at all. 

These blades usually have 2 sides, an angled side, and a flat side. Now from there, it’s pretty easy to figure out which side cuts and which does not, but it can still be confusing. 

Some blades also come with labels that indicate which side should be up. 

The angled/beveled side is the side which should be facing downwards or towards the grass, while the blunt, flat side faces the lawnmower dock. 

Which way is up?

Inspect your blade. Lawnmower blades should have two different sides: beveled or angled, and straight. 

The straighter edge is usually blunt, which means putting it on the wrong side can result in your grass not being cut or may even risk safety-related injuries arising.

You’re going to want the sharper beveled edge to be facing the ground, naturally, and the blunt edge should be facing the slot in the lawn mower’s deck. 

The blades, some more than others like mulching blades, also typically have some sort of arch that helps with cleaning up grass clippings. Unlike a vacuum cleaner which carries a bag, the secret of this is the shape of a blade, so those should be on the bottom. 

This is a pretty easy way to identify which side you should put the blade on, but if you’re still confused, check for other indications.

Manufacturers usually attach stickers or engrave wording that shows which direction the blades are supposed to say. “This Side Down” is a common one, sometimes just the word, “Bottom”.

Another indicator that something isn’t right is when the blade is wobbly or the machine is not functioning in the right way. 

Check if the blade is wedged in the lawnmower deck securely, if it wobbles, it can be a sign that the wrong side is up. You can also use additional tools to ensure that they are bolted on correctly to avoid risking any injuries.

Are all blades the same for each type of lawnmower? 

Standard lawn mowers usually have blades that are easier to identify which side is which, but other kinds of lawnmowers do not. 

Take for example the mulching blades. While these don’t really have indicators on which side is used for cutting and which side is facing the deck, you can usually tell because of the way they arch or curve.

Mulching is the ideal technique to use, mainly because these blades are able to do more tasks than a regular blade can. 

Regular lawn mower blades are typically designed to do two tasks — discharge grass clippings and tucking them away into a collection bag. Mulching blades can do both of these and one more thing.

What is mulching and why is a different blade required?

Mulching is considered the most environmentally-beneficial type of lawn mowing. It double-cuts grass and this usually involves enriching the soil and keeping its moisture, which benefits both the environment and the grass that grows on it. 

It also aids in keeping the weeds away and regulates soil temperature. Overall, your garden looks more polished with the added benefit of additional nutrients as well. Pretty cool! 

Mulching blades are usually different in appearance to regular blades, as they tend to look more curved or arched rather than regular blades which are just straight. This is what helps in cutting grass more than once. 

Despite this being incredibly convenient and an ideal type of mowing, it can also be higher maintenance. Regular lawn mower blades usually fling the grass clippings into the discharge-bag, while mulching blades keep the clippings within a mower’s deck. T

This can, later on, result in clogging the deck. You’ll need to watch out for that, as lawnmowers do require maintenance to some degree.

What happens if I install my blade the wrong way?

Most lawn mowers typically run on power, assuming they are the standard corded ones. Installing the blade can put your device at potential risk of damage to the dock and under part of the mower, damages to the blade itself, reduced performance, overheating, and eventually even the lawnmower not working at all.  

Other times the risk of injury to the user arises. Say you realize that your blade is inserted incorrectly, and you try to put it in the right way, remember to unplug your device from any outlets it might be connected to.

If it is powered by petrol try to empty the tank before switching the blades to avoid an accident. 

It saves so much time and money if incorrect blade installation is identified sooner rather than later. Some instances show that installing the blade the wrong way doesn’t really do any damage to the device, but it does significant damage to your lawn. 

Of course, the correct blade will cut your grass neatly and beautifully, but the wrong side usually results in an uneven mess. This can permanently damage your lawn overall because the unevenness can also mean uprooting grass that shouldn’t be. 

Some lawns take a lot of work and years getting them to look and grow the way you want them to, and with a simple mistake, it could ruin your hard work and have you start from scratch trying to repair the damage an honest mistake made. 


Despite being quite easily identifiable, installing your blade is incredibly important to your lawn’s look and health. Make sure to check for indicators or surfaces that will aid in the correct installation of your blades. 

If there is still significant confusion or signs of malfunctioning, it’s best to research your lawn mower’s brand and model or take the machine to a professional. 

Always unplug cords and empty petrol tanks to avoid accidental powering on of the device and risk hurting yourself.