Are Lawn Mower Blades Reverse Thread?

Lawn mowers are like any other machine in that they need to be properly maintained or they will fall into disrepair. An important component of lawn mower maintenance is removing the blades periodically to clean, and if necessary, sharpen them. A common question related to this aspect of mower maintenance is: Are lawn mower blades reverse thread?

There is a lot of information out there regarding this topic. Unfortunately, many of the answers you will find online are either unclear or the person offering the answer does not understand what “reverse threaded” means. So let me define what that means before I provide a definitive answer.

“Reverse Thread” Defined

Just what does it mean to say that lawn mower blades are reverse threaded? First of all, the phrase does not refer to the blade at all, but rather to the bolt that holds the blade in place. That bolt connects the blade to the drive train which spins the blade and enables it to cut the grass.

That bolt is either threaded in the standard fashion – which means you turn it to the right, or clockwise, to tighten it and to the left, or counterclockwise, to loosen it – or it is reverse threaded. Reverse threaded means you turn it to the left, or counterclockwise, to tighten it and to the right, or clockwise, to loosen it.

So, Are Lawn Mower Blades Reverse Thread?

Some are and some are not. It depends on the manufacturer. While there is a common belief that most are reverse threaded the fact is a majority are threaded in the standard fashion (turn right to tighten and left to loosen). Let’s take a quick look at individual manufacturers to see if their mower blade bolts are standard or reverse threaded.

Are John Deere Mower Blades Threaded in Reverse?

No. The bolt that holds John Deere mower blades in place is threaded in the usual fashion. To tighten it you simply turn it to the right, (clockwise) like you would any standard bolt. To loosen it, turn it to the left, or counterclockwise.

Are Craftsman Mower Blades Reverse Thread?

Yes. The bolts that hold the mower blades on a Craftsman mower in place are reverse threaded. That means that to tighten the bolt you must turn it to the left (counterclockwise), and to loosen it you must turn it to the right (clockwise). Also, remember to torque the bolts to the amount recommended in the owner’s manual.

Are Toro Mower Blades Reverse Thread?

No. The bolt holding the Toro mower blade in place loosens in the traditional manner, i.e. to the left, while it tightens to the right. Some Toro owners complain that this bolt is extremely difficult to loosen. If you find that to be the case apply some penetrating oil to the bolt and let it soak in for half an hour before trying to remove it.

Are Cub Cadet Mower Blades Reverse Threaded?

No. According to the Cub Cadet website, the bolt holding the mower blade in place is threaded in the normal fashion. That is, turn it right (clockwise) to tighten it, and turn it left (counterclockwise) to loosen it. These bolts typically have a 5/8 inch thread and need to be tightened to 70-90 foot pounds of torque.

Think Safety When Removing Mower Blades

Injuries are all too common when removing mower blades. If you assume the bolt on your blade is reverse threaded and it is not you could hurt yourself trying to turn it the wrong way. You might also tighten it so much that you will need a special tool to remove it.

Also, if your hand slips while trying to loosen a stubborn mower blade bolt it could contact the blade and cause a serious cut. So always wear work gloves when performing this task.

Final Thoughts

Unless you have a specific reason to believe otherwise (for instance; the owner’s manual states the bolt is reverse threaded) it is fairly safe to assume that the bolt holding your mower blade in place is threaded in the standard fashion, since most of them are.