Are Circular Saw Blades Reverse Threaded? Let’s Find Out Below

Last Updated On February 17, 2023

People, who are apparently new to using power tools often ask- are circular saw blades reverse-threaded? If yes, then why?

As you are already here, possibly you are looking for the answer too. 

Well, the answer is yes for a left-handed circular saw as its bolts tighten when turned counterclockwise. But a right-handed circular saw is not reverse threaded.

But what makes this distinction between a left-handed and a right-handed saw?

Don’t fret; we are here to explain that below. Without further delay, let’s make things easier for you to understand. 

What Do You Understand By Reverse Threaded?

The term reverse threaded means something is threaded in the opposite direction compared to its regular counterpart. 

For example, a regular bolt tightens when turned clockwise. But a reverse-threaded bolt tilts when you turn it counterclockwise.

Generally, most bolts are threaded for right-handed persons. Naturally, they run clockwise. 

However, unlike the typical threads, reverse-threaded bolts run in the opposite direction and they are designed for left-handers. 

Are Circular Saw Blades Reverse Threaded?

If you are talking about a left-handed circular saw, then yes, the saw blade is reverse-threaded.

For a left-handed circular saw, the blade usually turns clockwise. 

So, it goes without saying that you need to tighten the bolts by turning them counterclockwise. 

But that’s not the case for a right-handed saw though. In most cases, the right-handed circular saw blades turn counterclockwise. 

Therefore, you need to turn the bolts in the reverse direction, which means clockwise to tighten them. 

That’s why right-handed saws are not reverse-threaded.

Why Are Saw Blades Reverse Threaded?

A circular saw blade is reverse threaded to the bolt so that it doesn’t loosen easily.

In the case of a circular saw, we often see the blade connected to the arbor shaft.

The shaft and the saw blade must be well connected by the bolts to prevent severe accidents while working with the saw. 

That’s why the blade and the bolt must run in the opposite direction. 

If the blade turns clockwise, the bolts need to turn anti-clockwise to get tightened. And you must use the wrench clockwise to loosen them.

Nevertheless, the same thing happens in a left-handed circular saw. As the saw blade spins in the clockwise direction, the bolts tighten in the opposite direction. 

Just imagine what will happen if the saw blade turns in the same direction as the bolts. 

They will be unscrewed easily and cause severe accidents. But how severe? God knows! 

In order to prevent such mishaps, left-handed circular saws use the reverse threading technique.

How to Tighten a Circular Saw Blade?

For a circular saw, you might find the “righty-tighty, lefty-loosey” term misleading. 

To tighten a circular saw blade, you need to do quite the opposite actually. 

As these power saws have left-hand thread, which means reverse thread to attach the blades, you should turn the screws right to loosen them.

On the other hand, they should be turned left to be tightened.

How to Change a Circular Saw Blade?

Now that you know which circular saw blades are reversely threaded, let’s make you understand how to change a saw blade like a pro.

Here are the steps you should follow-

1. Unplug the saw first. That’s the most important thing to do whenever you need to change the blade. In the case of a battery-powered saw, you should remove the battery.
2. Now you should find out the wrench that came with your saw. In most cases, you should follow the user manual to locate the wrench.
3. In terms of a corded saw, it will be an open-end wrench. And you will get an Allen wrench for a cordless model.
4. With the wrench, you need to unlock the base plate to the lowest position and then lock it to that position. This will allow wider room around the bolts by which the blade is secured. 
5. At this point, you need to find the blade lock button. Usually, you will get it behind the upper guard.  
6. Now, it’s time to loosen the blade bolt by depressing the lock button. It would be best if you use the wrench to loosen the bolt and unscrew it.
7. But wait, which way should you turn the wrench? Well, the bolt will loosen in the opposite direction as the blade rotates and tighten in the similar direction the blade turns. So, if your saw blade spins counterclockwise, turn the bolt in the same direction to loosen it.
8. Usually, there will be an arrow on the upper or lower blade guard to point out which way the saw blade rotates. You just need to turn the bolt in the same direction. 
9. Once you unscrew the bolt, remove the outer washer first. Then carefully lift the old saw blade and take it out of the shaft.
10. Finally, you are going to install the new blade. But before you do so, don’t forget to check the inner washer. It must be free of debris.
11. Now, retract the lower guard and install the new saw blade onto the shaft through the base plate.
12. Things to remember, the new blade must be snug enough against the inner washer. And most importantly, it must rotate in the same direction as the arrow on the blade suggests. 
13. After that, replace the washer and the bolt. Secure them as tightly as possible. 
14. Congratulations! You are good to go with the new saw blade you just installed. 

Do Circular Saw Blades Go Clockwise or Counterclockwise?

Usually, a circular saw blade rotates clockwise as it cuts on the upward stroke. Cutting from the bottom up, the saw blade goes clockwise to keep the cut smooth and accurate.

Final Words

That’s all about whether circular saw blades are reverse threaded or not. Hopefully, you got your answer from the discussion above. 

For a left-handed circular saw, the blade is reverse threaded to be effective enough. And that’s why the bolt that secures the saw blade moves in the opposite direction of the blade.

Moreover, we discussed in detail how to change a circular saw blade. Hope it helps whenever you install a new blade in your saw.

Good luck!