When Should You Replace Carbon Brushes In Power Tools?

For avid home DIYers, you probably have several types of power tools in your arsenal to do minor fixes around your home or complete more complex home improvement projects on your own.

Hence, when your handy power tool starts acting up, it can be quite frustrating. And being the DIYer that you are, you’re probably doing the troubleshooting on your own. Since there are numerous working parts within a power tool, it can be hard to identify which part is causing the issue.

However, one of the first things you should look at is the carbon brushes since it is one of the common parts causing temporary problems.

What Is A Carbon Brush?

Replace Carbon Brushes In Power Tools

A carbon brush is a small part of the electric motor which conducts the electrical current between rotating and stationary wires inside the motor, ensuring a spark-free commutation.

It is an essential component for most power tools like angle grinders, drills, hedge trimmers, circular saws, electric planers, and dust extractors.

Its function of carrying current back and forth between the motor parts reduces damage to the motor. But due to friction, the carbon brush is prone to wear and tear.

Carbon brushes are often made of carbon or graphite and are available in different shapes and sizes, but they’re usually rectangular or square and feature grooves that guide them into place.

You Can Buy Replacement Carbon Brushes

Did you know that you can actually buy replacement carbon brushes? This stops you having to replace the power tools when the carbon brushes have worn out.

Retailers such as TDO Carbon in the UK specialise in replacement carbon brushes for power tools, helping you extend the life of your tools and save you money.

Signs It’s Time To Replace The Carbon Brushes In Your Power Tools


1. Low Performance

An inefficient performance is one of the early signs that the carbon brush needs replacement. Although low performance is a general sign associated with other malfunctioning parts, a worn-out carbon brush is the main culprit that reduces the overall power and performance of your power tool.

The general wear and tear on the carbon brush prevent it from connecting to the motors. This lack of contact causes an interrupted flow of current, thus, causing low power generation in your power tool. Your tool may need a little jolt to get going, or its RPMs may have slowed down.

For seriously damaged carbon brushes, the power tool will stop working.

2. Spark Generation

Sparks when using a power tool like an angle grinder against metal material are common. However, sparks within your power tool itself aren’t normal and are dangerous. When you notice your power tool sparking, ensure to switch it off right away to prevent electric and fire hazards.

In general, sparks within your power tool are caused by a worn-out carbon brush. Since carbon brush acts as a middleman between the motors, a thin and worn-out carbon brush can cause motor parts to connect and cause sparks. It may also be caused when carbon brush specks are deposited on the channel and block the air vent.

You can monitor the sparks via the cooling vents of your tool, helping you gauge if the carbon brush damage is getting worse.

3. Burning Smell

Another sign that tells you to replace your carbon brush is a burning smell. Most power tools produce friction and heat when in use. This process can create a burning smell, especially when the tool is used for longer periods.

That said, if a burning smell arises after just a few seconds or minutes of using the tool, you should check the condition of your carbon brush. A damaged carbon brush creates friction between motor parts, causing an unwanted burning smell in your machine.

Sometimes, a burning smell is often accompanied by sparks or smoke, indicating that your carbon brush has completely worn out.

In this case, switch off the tool immediately. Let the parts cool off, and then inspect their parts and carbon brush. If the carbon brush is the culprit, make sure to replace it right away.

4. Physical Discoloration Or Damage

Inspecting the air vent of your power tool can show signs of whether or not your carbon brush will need replacements.

Generally, discoloration due to overheating, visible crumbles, and heavy release of carbon specks are indications that your carbon brush is wearing out and needs replacement.


As you can see, carbon brushes have a critical function in your power tool. That said, due to their functionality and design, carbon brushes are prone to wear over time.

By knowing the signs that your carbon brush is worn out and needs replacement, you can prevent frustrations when your power tool suddenly stops working and finish your project without interruption.

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