The circular saw is one of the most important and versatile tools in carpentry. With that being said it can also be one of the most dangerous tools. Since it is so mobile it can be hard to handle the saw while making cuts.
If you have ever used a circular saw then you have probably experienced kickback before. It is unfortunately pretty common and can be very dangerous. The good news though, there are steps you can take to help prevent it from happening.
As someone who has worked with circular saws for many years, I know firsthand how important it is to take precautions to prevent kickback. I will discuss the causes of kickback and provide tips for how to avoid it. By following these guidelines, you can use your circular saw safely and effectively, without putting yourself or others at risk of injury.
Circular Saw Kickback
Circular saw kickback is very dangerous. To prevent kickback ensure the material is propped up and has support 2-3 inches on either side of saw. Make straight cuts and limit blade twisting. Start the blade then initiate the cut and wait to remove the saw until blade is not spinning.
What is kickback?
Circular saw kickback is a dangerous and sudden reaction that occurs when the saw blade catches on the material being cut. This caused the blade to pinch and the saw is thrown back towards the user. It can happen with any saw but is most common when using a circular saw. This is because the circular saw requires you to move the saw through the material you are cutting. Other saws like table or miter saws are more stationary and allow for less user error.
When using a circular saw the blade spins clockwise. So when you stand behind the saw it is spinning towards you to cut the material. When the blade gets pinched by the material it is cutting, the saw gets thrown back in the direction of the blades rotation. This most commonly means the saw is coming directly back towards you.
I’ve experienced circular saw kickback myself, and it’s a frightening experience. The saw can be thrown out of your hands, causing injury to yourself or others nearby. It can also cause damage to the material being cut or the saw blade itself.
So lets take a look at what causes this kickback to occur and how you can prevent this from happening.
Causes and prevention of kickback
There are a number of different reasons why kickback can occur. Lets go through the most common ones and how to prevent it from hapenning.
1. Support for the material
This is by far the most common cause of circular saw kickback. The way you support the wood that you are cutting is very important and goes a long way in safe saw handling.
When support for the material you are cutting is not adequate it can lead to blade binding. This is not good and almost always leads to saw kickback.
When cutting the saw makes a channel that the blade can safely sit it, this is known as the kerf. This area is the safe zone for the blade. In the kerf the blade can rest (while moving or stationary) with no contact from the material. So it is important to keep the kerf as wide and open as possible throughout the entire cut.
Make sure the material you are cutting has supports close to the cut. Obviously not so close that the supports will be cut but the closer to the cut the better. This will keep the cutline from collapsing as you cut.
If you do not have proper support the material will bow as the saw passes through it. When the material bows this throws the cutline off. Once the cut line is compromised the blade will become squeezed and almost certainly cause kickback.
Make sure you have some support under the weight of the saw. The weight of the saw is in the motor which in most cases is just to the right of the blade. If there is not enough support for the weight of the saw that will cause the wood to bow while you cut.
My general rule of thumb is to place supports about 2-3 inches on either side of the cut path. This will ensure the wood does not bow and significantly reduce your risk of kick back when cutting.
Lastly, you also want to make sure you have supports on the far ends of the material you are cutting. This will ensure nothing moves during the cut. It also keeps the cut material in place after the cut. That way nothing drops during the cut and alters the weight and or cut path.
2. Poor saw use
User error when it comes to circular saws is unfortunately a major issue. If you are not confident and or practiced when it comes to using a circular saw it can lead to dangerous mistakes.
One of the most common mistakes I see is twisting of the saw. It does not take much of a twist either. A small twist left or right can lead to the blade contacting the edge of the material and binding to occur. Remember a moving blade does not like binding and this significantly increases the risk of kickback.
You want to make sure to push the saw in a perfectly straight line. This can be difficult since it is so freely moving. There are a number of tools out there to help you improve your ability to make these straight cuts.
Or you can use a level, a clamp and some scrap wood to ensure a straight cut.
Adjusting the saws blade depth or bevel setting while cutting is another user error and huge risk. This should never be done while making a cut. It seems like a no brainer but I have seen it done before. Make sure you adjust the blade depth or bevel setting prior to cutting and leave it there throughout the cut. Moving components of the saw are meant to stay locked when operating the saw.
Another mistake I have seen is when using circular saws that have power cords. Many saws these days are battery operated which eliminates this issue. But if using an electrical saw make sure there is enough slack in the cord for the entire cut.
If the cord gets caught on something or does not have enough slack it will stop the saws motion. This commonly leads to twisting or movement of the blade. When making longer cuts I like to hold the cord in my hand (against the saw) to ensure it does not get caught.
3. Failure to prop up your cut
When using a circular saw most of the time the blade will extend through the material you are cutting. Because of this you must prop the material up that you are cutting. If you do not the blade will contact anything in its path and lead to binding and or kickback.
The best way to do this is to use some scrap wood. You can place the scrap wood under the material and out of the cut path. This will allow your blade to pass through the material you want to cut and limit contact with any other surfaces.
As you can see above the scrap wood technique allows you to prop closer to the cutline. The base of most sawhorses will limit how close they can be to the cutline.
If you are using scrap material you can place the blocks in the cut path. The blade of the saw will pass through the scrap wood but will prevent unwanted contact with other materials.
4. Removing saw while blade still spinning
This will almost always lead to kickback. The reason is because when you lift the saw up you rarely do in a straight line. This will lead to the blade contacting the material being cut and kickback will occur. Make sure that the blade has completely stopped moving prior to removing it from the material. Depending on the saw brand you use, the blade will take a couple of seconds to come to a complete stop. Practice patients and double/triple check prior to removing.
This is also a good way to mess up a good cut. The blade will nic up the material on the way out.
5. Starting blade when in contact with material
Never start the saw when the blade is already in contact with the material you are cutting. When the blade is contacting something and then started it almost certainly leads to a dangerous kickback.
This is most commonly seen when a cut is started and then you have to stop to adjust. If you have to make adjustments mid cut make sure you back out of the cut a couple inches so the blade is free. Then once the blade is spinning full speed, continue with your cut.
This will also help limit the stress placed on the blade and the saw.
6. Setting saw blade too deep
When cutting the blade of the saw has to extend through the material. However, it does not have to extend too deep. You want to make sure the blade extends past the material by less the 1/4th of an inch. This will allow adequate cut depth and limit the chance of the blade contacting an unwanted surface. Also anything greater then 1/4th of an inch leads to more blade surface area that can bind.
Something to keep in mind that there is no way to totally eliminate kickback from happening. Even the most experienced circular saw users have kickback happen occasionally. However if you focus on the tips and tricks listed above you will significantly reduce the risk. You want to set yourself up for success to significantly reduce the possibility of kickback happening.
Safety when handling a circular saw
There are some important safety measures to take when using a circular saw. These will significantly reduce your risk of injury and lead to a smooth cutting experience.
It is important to remember that a circular saw is a basically a free hand table saw. They have lots of power and are only controlled by your hand/arm. Circular saws have no fixed path like miter and table saws do. With all that in mind lets jump into the safety tips.
Never get in the cut path
Under no circumstance should you ever put a body part in the saws cut path. This means NEVER put your free hand or a foot in front of or behind the saw. Remeber because of kickback the cut path also includes behind the saw/blade.
Also make sure you never reach underneath the piece you are cutting. Always make sure to keep your hands on top of the surface you are cutting. This will ensure your hands to do not enter the cut path from below.
You want to make sure that you are standing behind the saw and just to the left or right of the cut path. This will give you the most control and is the safest positioning should things go wrong. It is best to try and keep both hands on the saw at all times. This will help secure the saw when cutting and ensure a free hand never enters the cut path. Below you can see the most ideal cutting position pictured.
In order to safely put both hands on the saw you should always use clamps to secure the material. This is essential when using a circular saw. Clamps will allow you to stabilize the material without putting your hands in jeopardy of getting cut. DO NOT TAKE SHORT CUTS, USE CLAMPS.
Hopefully you found this helpful when using your circular saw
- What is kickback
- Causes and prevention of kickback
- Support for the material
- Poor saw use
- Failure to prop up your cut
- Removing saw while blade still spinning
- Starting blade when in contact with material
- Setting saw blade too deep
- Safety when handling a circular saw
- Never get in the cut path
If you found this to be useful, please let me know in the comments!
A current home owner and dad of two, who loves to fix things. I have spent countless hours fixing and repairing things around the house. I started this blog to share my knowledge with you. I hope you find what you are looking for!