The Ultimate Guide to Circular Saw Brush Sparking (Causes, Signs, and Fixes)

Circular saw brushes perform heavy duty when the tool is in motion. Such duty can be hindered when the brushes start sparking.

The prime reasons for such sparks are worn-out brushes or the misplacement of them. When the brushes are in dilapidated condition you must replace them with new ones.

If the circular saw brush sparking is bothering you, you have landed on the right article.

Circular Saw Brushes Sparking

Circular Saw Brushes Sparking

Circular saw brushes are in charge of transferring electrical current from the stator, which is the motor’s fixed component, to the armature, which is the motor’s revolving component. The armature, which spins the blade, receives energy from the power supply through the brushes.

Sparking may occur if the brushes start to lose their effectiveness over time. It’s crucial to remember that some sparks with circular saws are typical, particularly when they initially start up. The sparking only becomes an issue if it is severe or persists while the saw is being used.

The brushes must be replaced if they are depleted. For your particular saw model, replacement brushes are often available and not too difficult to install. However, it’s crucial to make sure you get the appropriate replacement brushes for your saw because using the incorrect ones could result in additional damage.

Reason For Circular Saw Brushes Sparking

Circular saw brushes can cause sparks for lots of reasons. To comprehend the situation in depth you first need to troubleshoot the problem by diagnosing the root cause. Let’s explore the reasons that can initiate sparks in circular saw brushes.

Worn Down Brush

When using a circular saw for several years, the brush gradually falls out and becomes dilapidated over time. When the brushes are not in suitable condition, their interaction with the armature becomes less frequent. This irregularity creates tension in the brush and causes sparking.

Brushes Misplaced

Another reason could be that the brushes are not seated correctly, which can also cause sparks. Many times, the brushes are misplaced for debris that has been stuck inside. Also, the high-power motors can shift the position of the brushes in a circular saw. You can examine the seating of the brushes by detaching the brush caps and reviewing the brushes themselves.

Damaged Armature

If the brushes are not worn-out and are seated properly, instead of focusing on the brushes only, you need to shift your focus to the surroundings. An armature can be a reason to make the brushes spark. How? Sparking may result from disparate contact between the brushes and an injured armature.


In addition to the reasons I have listed, a commutator issue might also be a contributing factor to sparking. The part of the armature that the brushes make contact with is called the commutator. Sparking may occur if the commutator is filthy or broken.

Signs Of Damage To Circular Saw Brushes To Look For

Damage in circular saw brush can serve two purposes. It can indicate to you that something is not right, and it can give you the opportunity to troubleshoot the surroundings, not only the circular saw brushes. So, let’s learn how to diagnose the signs in circular saw brushes.

Worn-Out Brushes

There is a very easy way to identify worn-out brushes. The brushes will, over time, become shorter and shorter. When the brushes are less than half of their original size, you can finally declare them worn out.

Frayed Or Broken Wires

Over time, the wires that link the brushes to the circular saw may get frayed or damaged, which may result in sparking and electrical problems. This happens when the wires are overheated and too worked out.

Chipped Brushes

Brushes that are chipped, broken, or otherwise damaged may not make good contact with the armature, which can result in sparking. In addition to the size of the brushes, you also have to take note of the shapes of them.

Burnt Or Discolored Brushes

If the brushes seem burnt, discolored, or smell strong, the saw may be overheating or having other electrical problems. This is the easiest way to spot a damaged brush that causes the sparkling.

How To Repair A Damaged Circular Saw Brush?

The best option for repairing damaged circular saw brushes is by replacing them. There are separate brushes you can purchase in your local market or on Amazon. However, as mentioned earlier, you must make sure the new brush is compatible with your circular saw model. Once you have found one, you can replace them by yourself following this easy tutorial.

Unplug The Saw

Make sure the circular saw is detached from any electrical supply. Remove the battery if the circular saw is cordless. Be mindful to unplug your circular saw from the power source before starting any repairs.

Take Off The Brush Caps

Brush caps are securely covering the brushes. Use a screwdriver to locate the brush caps on your saw. Slowly unscrew the caps and take them out. You can spot the brushes inside.

Take Out The Brushes

Now that the brush caps are out, carefully take out the saw’s brushes. To install the new brushes correctly, pay attention to how they are seated.

Set Up The Fresh Brushes

Set up the fresh brushes in the same location as the previous ones. Ensure that they are placed correctly and are in close contact with the armature.

Replace The Brush Caps

After installing the new brushes, replace the brush caps and firmly tighten them. If the brush caps are in good condition, you can use the previous ones as well.

Test The Saw

Reconnect the saw to the power or batteries and give it a test run to ensure that the sparking has ceased, and the repair was effective. Before testing the saw, clean the internal components and make sure they are free of sawdust and debris.

Some Tips To Remember

  • To prevent the circular saw brushes from sparks, you must inspect the brushes regularly. Even if there are no or fewer sparks, replace the brushes when they are worn out or half of their initial length.
  • Sawdust and debris are the prime reason that creates erratic contact with the armature. This eventually leads to sparking. So, make sure to clean the circular saw regularly.
  • Stop overloading the circular saw. Use the saw correctly by following the manufacturer’s guides. Forcing the saw through the material creates unexpected tensions in the brushes.
  • Use the correct blade on the circular saw. A wrong-sized and shaped blade creates too much pressure on the circular saw motor. This leads to sparks on the brushes.
  • Don’t use cheap, low-quality brushes on your circular saw. Those brushes wear down quickly and create sparks.

People Also Ask


How often should I replace the brushes?

How frequently you use your circular saw, the sort of job you’re doing, and the state of the brushes can all affect how often you need to change them. Generally speaking, you might need to change the brushes after 50 to 100 hours of use. If the brushes show any symptoms of deterioration, such as fraying or breaking, you should replace them immediately.

What should I do if I’m experiencing excessive sparking?

There are a few things you may do to fix the problem if your circular saw is sparking excessively. Verify the brushes’ condition and that they are making excellent contact with the armature. A weak or unstable power source to the saw might result in excessive sparking. Check to see that the saw is connected to a reliable power source and that the cable is in excellent shape.

What are the correct replacement brushes for my saw?

Depending on the brand and model of your circular saw, the proper replacement brushes must be used. You can consult the operator’s handbook for your saw or get help from the manufacturer to identify the proper brushes.

As an alternative, you may try conducting a web search for replacement brushes using the brand and model of your saw. You might be able to obtain the right brushes using the online replacement parts that a lot of stores and producers provide.

Final Words

Circular saw brush sparks can’t bring good fortune to your circular saw. Indeed, it is normal in some situations, but you must not let it grow frequently. You must nip the issue in the bud by identifying the root cause and replacing the brushes.


My name is Michael M. Militello, and I want to help you find the right tools and the best products for your next project! As a professional tool expert here in Houston, TX, With my vast tool experience, I can help you choose the right brand, model, and size for the job. Please feel free to contact me with any questions you may have. You can reach me here on my blog and also on Facebook, Twitter , and Pinterest. I look forward to hearing from you!

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