Are Circular Saws Reverse Threaded? Here’s What You Need To Know

Circular saws are a staple tool in any DIY enthusiast’s arsenal. They are versatile, powerful, and can make quick work of any cutting task.

However, when it comes to changing the blade on a circular saw, things can get a little confusing. The old adage of “righty-tighty, lefty-loosey” doesn’t always apply, and you may find yourself struggling to figure out which way to turn the bolt.

In this article, we will explore the question of whether circular saws are reverse threaded and provide you with some tips and tricks for changing your saw blade with ease.

So grab your safety goggles and let’s get started!

Are Circular Saws Reverse Threaded

The short answer is yes, some circular saws are reverse threaded. But it’s important to understand why.

The “hand” of the thread, or the direction in which it tightens and loosens, is critical in designing a rotating device such as a saw, router, or drill. In order for the mounting bolt to stay tight, the threads on the bolt must tighten “opposite” of the rotation of the blade. Otherwise, the turning of the blade would eventually cause the bolt to turn out.

Therefore, if the blade on your saw rotates counterclockwise, then the bolt is tightened clockwise. So if your blade turns counterclockwise, then you should loosen the bolt counterclockwise. Right-handed circular saws all have blades that turn counterclockwise, while left-handed saw blades turn clockwise.

It’s important to note that not all circular saws are reverse threaded. Right-handed circular saws typically use a left-hand thread screw to attach the blade, which is the opposite of “righty-tighty, lefty-loosey”. This means a circular saw blade screw must be turned to the right to loosen and to the left to tighten it.

Understanding Thread Direction

To understand thread direction, it’s important to know that all bolt threads have a helix, which is how they spiral up the bolt cylinder. When tightening a bolt, its helix will turn in one of two directions, clockwise and counter-clockwise. Most bolts have a right-handed thread and turn in a clockwise direction as you screw them in. The threads of such a bolt appear to angle upward to the right, which is called pitch.

Reverse-thread bolts, on the other hand, have a left-handed thread and turn in a counter-clockwise direction when tightened. The threads of these bolts appear to angle up to the left. When a tool or part is reversely threaded, the tool’s threads run in the reverse direction of their more common counterpart. For example, since most bolts thread with a right-handed person in mind, they run clockwise.

Circular saws work similarly to bolts. Right-handed circular saws are not reverse threaded. However, left-handed circular saws are. Conversely, the blade secures with a bolt of the opposite threading. So a left-handed saw would require a regular threaded bolt. A right-handed circular saw, on the other hand, would require a reverse threaded bolt.

It’s also worth noting that blade direction and thread direction are related. Right-handed circular saws have blades that turn counterclockwise and require a reverse threaded bolt to secure them in place. Left-handed circular saws have blades that turn clockwise and require a regular threaded bolt to secure them in place.

Common Thread Directions For Circular Saws

When it comes to circular saws, it’s important to understand the common thread directions for attaching the blade. As mentioned earlier, left-handed circular saws use a regular threaded bolt to secure the blade, which means that the bolt must be turned counterclockwise to loosen and clockwise to tighten. On the other hand, right-handed circular saws use a reverse threaded bolt, which means that the bolt must be turned clockwise to loosen and counterclockwise to tighten.

It’s also worth noting that table saw blades can have different thread directions depending on the tilt of the blade. If the blade tilts to the left, it will not be reverse threaded, but if it tilts to the right, it will be reverse threaded. This is because a right-tilted blade sits on the left side of the table, while a left-tilted blade sits on the right.

Understanding these common thread directions is essential for properly maintaining and using your circular saw. Always refer to your user manual for specific instructions on how to attach and tighten your saw blade, and never force a power tool. By following these guidelines and taking proper care of your saw, you can ensure safe and efficient operation for years to come.

Tips For Changing Circular Saw Blades

Now that you understand the importance of the thread direction when changing circular saw blades, here are some tips to help make the process easier:

1. Always unplug the saw before changing the blade. This ensures your safety and prevents the saw from accidentally turning on while you’re working on it.

2. Make sure you have the correct blade for the job. Each blade has specific information on its face, including the type of material it’s best for, the thickness of the material it cuts, and the number of teeth it has. Take a picture of your circular saw blades and file it away for future reference.

3. Before removing the old blade, take note of its orientation. The teeth should be pointing up, as circular saws cut on the upward stroke.

4. Loosen the bolt in the same direction as the arrow on the upper or lower blade guard for blade rotation. For right-handed circular saws, loosen counterclockwise. For left-handed circular saws, loosen clockwise.

5. Once the bolt is loose, remove the outer flange and blade lock button if applicable.

6. Carefully remove the old blade and replace it with the new one, making sure to orient it correctly with the teeth pointing up.

7. Replace the outer flange and blade lock button if applicable.

8. Hand-thread the arbor bolt back on and tighten it with a wrench, being careful not to over-tighten.

9. Rotate the guard closed and test your new blade to ensure it’s properly installed.

Following these tips will help ensure you safely and correctly change your circular saw blades, no matter what direction they’re threaded in.

Safety Precautions To Keep In Mind

When it comes to using a circular saw, safety should always be a top priority. Here are some important safety precautions to keep in mind:

1. Before handling any power tool, including a circular saw, put on safety equipment. A good hearing protection is necessary, as well as safety goggles to protect your eyes from the dust produced while cutting. The dust produced can also be harmful to you when inhaled into your lungs, so get a good respirator to go with the rest.

2. Always wear eye protection when operating a circular saw. Wear a dust mask and ear protection if the situation calls for it.

3. Avoid loose clothing, hair or jewelry that can be pulled into the saw.

4. Stand to the side when cutting to avoid potential kickbacks. Don’t overextend—move your feet so that you are always balanced and in full control.

5. Check the blade for sharpness—sharp blades work better and are safer. Check that the blade cutting nut has not been over-tightened. Only change blades when the saw is disconnected from the power source.

6. Check the cutting surface for metal objects like nails or screws.

7. Set the cutting depth as shallow as you can and don’t allow the blade to protrude more than a little below the stock being cut.

8. While you can use a circular saw with just one hand, always use with both hands for maximum control. This also requires you to clamp down work pieces so that they don’t move while you are cutting them.

9. Always check your circular saw before use to ensure that it is in perfect working order.

10. Some workers alter the lower guard by tying or wedging it open. Do not do this—rather leave the guard to pivot so that the blade is always safe.

11. If your circular saw blade catches on thin-shave cuts or angled cuts, rotate and hold it open with an extended fingertip while still keeping both hands on the saw.

12. Always wait for the blade to stop moving before setting the saw down on your work surface. Getting a circular saw with a blade brake will reduce your wait times.

By following these safety precautions, you can help ensure a safe and successful use of your circular saw. Remember that improper use of any power tool can be extremely dangerous and can cause serious injury or damage, so always err on the side of caution and take the time to do the job right.