Which Side of Mower Blade Faces Down? (Solved & Explained!)

When you are installing a new mower blade, the side that faces down will typically be marked with a sticker or with writing. The writing might list the model number or read ‘this side down’ or even ‘bottom’ to help you with installation, but if you don’t see these then simply look at the edge. The edge of the blade should be facing the grass.

Improper installation happens every day and it can damage not only your lawn, but sometimes even your mower! For the remainder of this article, we’re going to answer the questions we hear the most about installing so that you’ll know how to install your blades perfectly every time. Let’s take a look at what you need to know!

What is the trailing edge of a lawn mower blade?

‘Trailing edge’ is mower blade terminology that describes a curved portion on some mower blades which arcs up in order to better lift grasses. With the high-speed turning, the curvature creates a bit of a draft that lifts those clippings to send them out of the rear or side discharge of your mower, where it’s emptied into a bag or simply deposited on your lawn.

Does a lawn mower blade turn clockwise or counterclockwise?

Most blades on the market are designed to rotate clockwise. Remember that when you are viewing this from below, it will look like it’s counter clockwise. If you aren’t sure which direction your particular model is supposed to turn the blades, look for your side discharge chute.

If it is on the right side and also angled backwards, then your mower blades turns clockwise.

Which way do mulching blades get installed?

Installing mulching blades is a piece of cake – if you know what to look for. Check the blade for writing and we are looking for either a model number or the word ‘bottom’. When you see one of these, then this indicates that you are looking at the side that need to be facing the ground.

Bolt the blade in place with the writing facing down and you are ready to go!

Which side of mulching blade goes up?

Mulching blades will have a set of spikes or ‘points’ on them and when you spot these, then you’ll know immediately how to install your blades. The points need to be facing upwards, not at the ground, so simply bolt your mulching blades in place with these points facing up and you are ready to mulch the lawn at your soonest convenience.

Do you have to time mower blades?

No. You will not need to time your mower blades as the tips of the blades are designed to avoid collision, no matter how they are installed. If you attempt to time the blades they’ll simply just move around on their own. So, install your blades and skip any attempts at timing – it is neither useful nor necessary to do with your mower.

Are mower blades reverse thread?

Yes. Most mower blades, by design, are reverse thread. This ensures that they are stoutly affixed to the drive so that the rotation required for mowing doesn’t loosen up the bolts that are securing the blades in place.

That said, there are some exceptions, although these are rare. If you aren’t certain, a quick call to your manufacturer or consulting your owner’s manual should allow you to quickly confirm if this is the case.

What happens if you put lawn mower blades on upside down?

This is something that actually happens quite often. If mower blades are installed upside down, then they can not only damage the lawn, but even the mower itself.

It is best to look for writing on the mower blades or manufacturer instructions if this is not present. If you’ve just installed new blades upside down, they’ll typically be noisy and rip up the lawn, so you’ll notice very quickly if this is the case.

What is beveled side of blade?

When you hear the term ‘beveled edge’, this is simply referring to the side of the blade that is edged and angled and which actually cuts the grass. It is easy to spot, as the edge will only be on one side (never sharpen mower blades on both sides, only the one is used).

Are lawn mower blades righty tighty?

Yes. The blades are designed to turn clockwise, so if you are trying to loosen the bolt to switch out the blades, then you need to turn left, or counterclockwise. When tightening the new blade onto your mower, then the ‘righty tighty – lefty-loosey’ rule still applies. Turning the bolt right will secure it tightly so that you will be ready to safely use your new blades.

Are Lawn Boy mower blades reverse thread?

Yes, more often than not, Lawn Boy mower blades are going to be reverse threaded.

In order to loosen the bolt when changing blades on your Lawn Boy, you will want to put on gloves and hold the blade in place, while turning the bolt left (counter clockwise) and after fitting the new blade in place, simply pop the bolt back on and turn it to the right to tighten it (clockwise).

Are Cub Cadet mower blade nuts reverse thread?

Yes. The 5/8-inch nuts on the Cub Cadet mower blade need to be turned left to loosen them and right to tighten them. They are standard right-handed threads and moving them will require a force of approximately 70 to 90 foot-pounds of torque in order to loosen them enough for changing out and to tighten the new blades securely in place.

When should I replace my mower blades?

Mower blades should be replaced every 100 to 200 hours of use. This generally comes out to once a year, if you are mowing regularly, and your ‘mileage’ will vary based on the make and model of your blade.

Some commercial quality blades last much longer, sometimes up to 400 hours of work use, due to the incorporation of tougher metals and superior design builds, so be sure to check what your manufacturer recommends if you’ve purchased a specialized blade, rather than a standard.