Are Mower Blades Reverse Thread? (Solved & Explained!)

Yes, most mower blades are reverse threaded. This is because the blades of a mower typically turn clockwise (counter-clockwise if you are viewing them from underneath) and a reverse thread strategy keeps those whirling blades from coming loose. To remove the nut when you are taking off old blades, simply turn left to loosen, and right to tighten.

In this Mower Blade Maintenance FAQ we’ll answer some more of the most commonly asked questions that receive on changing out your blades, what can happen with an improper install, and more – let’s take a look at the facts that you’ll need to get it done quickly and the right way very time!

How do you remove a stubborn lawn mower blade?

First, remove your plug wire and turn off the gas feed if you’ve got a tap, and set your mower on its side, carb-side up so that you don’t leak gas. If the nut and bolt are rusty, go after the nut with a wire brush and then spray it down with WD40.

Let the WD40 soak in for a few minutes and try to loosen the nut again. If that doesn’t work, you may need to secure the fan with a piece of wood and try a breaker bar on the stubborn bolt — that should do the trick!

Are Cub Cadet mower blade bolts reverse thread?

Cub Cadet mowers typically have a right-handed thread to them, which simply means that you need to turn it clockwise to tighten it up and counter-clockwise in order to loosen it. The 5/8 inch bolts used by Cud Cadet typically employ 70 to 90 pounds of torque pressure to secure the nut properly, so make sure that you put it back on good and tight.

Are Scag mower blades reverse thread?

Yes, if you have a Scag mower, then expect it to be reverse threaded. This means that you will be tightening it to the right and loosening to the left, exactly in the same fashion that with learned with the classic phrase ‘righty tighty, lefty loosey!’

Are Craftsman lawn mower blades reverse threaded?

For Craftsman standard mowers, your thread is going to be a standard, right-handed thread, which means that you will need to turn the nut counterclockwise in order to loosen it, and you must turn it clockwise in order to tighten the new blades on which you have just installed.

Do all mower blades turn counterclockwise?

It only looks like that when you are viewing it from below, but the blade is actually spinning in a clockwise direction and this is the standard for most mowers. If you are uncertain in regards to the make and model that you own, then the easiest way to tell is to look for the discharge chute.

If it’s on the right-hand side of the mower and it’s facing back, then you can rest assured that the blade on your mower turns clockwise during normal operation.

How do you know which side of a lawn mower blade is up?

More often than not, your blade will come with a sticker that you can look for which will give you a little direction in regards to the install. Look for one of these and it will say ‘bottom’ or perhaps ‘this side up’, but if you don’t see a sticker at all then look for the wings on the mower blade.

These should be facing up when installing the blade properly.

How do you remove a lawn mower blade without removing the deck?

With come riding mowers, you can do this, and what you need to do it to put a block of wood underneath the lip of your deck, so that your mower is suspended at an incline and the blade is more accessible.

Keep the blade from moving by holding it in place with a C-clamp and this should allow you to loosen and remove the blade and put in your new one without removing the deck.

What happens if mower blades are upside down?

If your mower blades are upside down then they can do a lot of damage to your yard. Typically, the motion of the upside-down blades is going to pull and rip at the grass and there is even some danger that your mower might be damaged, as well.

Always make sure that the wings of the blade are facing upward and check them for sticks or writing – more often than not, you’ll see a reminder such as ‘this side down’ to help ensure proper installation of a new mower blade.

How do you know if mower blade is upside down?

It will apparent very quickly if the mower blade has been installed upside down. It will sound different, for one thing, and when you attempt to mow then the incorrectly aligned edge never hits your grass – resulting in tearing, ripping, or otherwise damaging your yard.

Mower damage is also a possibility, so if you see this happening then stop your mower immediately and check the blade and reinstall if this is the issue.

Which side of mulching blade goes up?

When you are installing mulching blades, look for the ‘teeth’ on the mulching blade. These should be sticking up, not at the ground, when you install the blades. Most mulching blades will have writing on them that reads’ bottom’ or ‘towards grass’ in order to help you to avoid this, so if you just got a set of mulching blades then look for these.

How often should you replace lawn mower blades?

Standard push mower blades, provided that you have been keeping them clean between mowings and sharpening them every 20 to 25 hours, should have an operational worklife of 100 to 200 hours. Some blades that you can purchase are available with stronger metals or alloys, and these can actually last up to 400 hours before needing replacement.

Does a new lawn mower blade need to be sharpened?

No. A newly purchased lawn mower blade will come from the factory already sharpened and balanced perfectly. Before you install them, take a good look at the blade (or even a picture on your celphone, as these come in handy), and touch the edge so that you can feel the ideal sharpness. Don’t worry, it’s not sharp enough to cut you.

This way, when you need to sharpen the blade, you’ll know exactly how sharp it should be and you’ll have an idea about the proper balance.