How does a Chain Brake Work on a Chainsaw? Detailed Guide

Knowledge Based

In the world of chainsaws, kickbacks are like those unexpected storms on a rough sea that can throw a ship off course. And if you’re a beginner, you gotta have some know-how of handling them to avoid any injury.

That’s where the chain brake comes in.

The chain brake is one of the many safety features in a chainsaw you should know about. As the name suggests, chain brake specifically stops the rotation of the chainsaw cutting chain in case of any sudden movement or kickback.

Did you know MBIE passed a notice on 24 June 2012 that says,” It is prohibited indefinitely to sell or supply a chainsaw without a chain brake.”

You see the importance?

So, without any further ado, let’s learn more about the working of chain brakes to better understand when and how to use them.

working of chainsaw chain brake explained

How does a Chain Brake Work? | Chain Brake Components

A lever is located on the top of your chainsaw’s front-hand guard. Pulling this lever forward activates the chain brake.

The chain brake system works by tightening the chainsaw’s brake band around the clutch drum. The engagement of the brake band in a running chainsaw causes friction, eventually making the chain stop rotating.

Here are 3 components that play along in the working of chain brake:

Lever/Brake Handle

The brake handle is the lever you’ve got to pull to activate the chain brake. It fires up the chain spring to hold the brake band around the clutch drum, preventing the rotation of the cutting chain.

Stihl chainsaws typically have integrated chain brakes, whereas Husqvarna brakes are located on the sprocket cover. While there are differences in locations, the basic operation of both is the same.

Brake Band Spring

The brake band spring is responsible for keeping the band tight against the clutch drum when the brake is disengaged.

The spring’s additional purpose is to keep the brake handle in place when not in use, preventing the chain brake from accidentally engaging during normal operation.

Brake Band

The brake band is a heat-resistant loop of metal that wraps around the clutch drum of the chainsaw. When you pull the chain brake (lever), the band starts encircling itself tightly to the surface. This creates friction that stops the rotation of the cutting chain.

Types of Chain Brakes

Most saws have two types of braking systems: mechanical braking systems and inertia braking systems. Let’s discuss both and see which one is the best;

Mechanical/Manual Chain Braking System

The name speaks it all. Yes, you would need to pull the trigger/liver of this braking system. It is common in many beginner and professional chainsaw operators because it is affordable, easy to use, and does not require any additional effort from the user to engage.

Inertia Chain Braking System

You can call it an automatic braking system. Some kickbacks are abrupt and powerful. Most people fail to react quickly enough to activate the chain brake manually. This brake is designed to engage the brake handle, brake spring, and band automatically through the force of inertia.

Which one is the best?

Both inertia and manual chain brakes are effective at stopping the rotation of the cutting chain and preventing injury to the user.

However, if you’re a beginner, manual chain brakes are more difficult to operate. Tho, they offer precise control and can be engaged at any time. Still, it’s not for you if you are unaware of your surroundings and potential hazards.

On the other hand, Inertia chain brakes are generally easier to use and require less effort from the user to engage.

The ideal chain brake for you will ultimately depend on your preferences and level of experience. When using a chainsaw with a chain brake, it’s crucial to pick one you feel confident using and always take the necessary safety precautions.

Let’s take a look at the explanation on Chain Brakes given by Stihl NZ:

What Makes a Chain Brake More Aggressive?

The aggressiveness of a chain brake refers to how quickly and forcefully it engages when kickbacked. A more aggressive chainsaw brake will engage more swiftly and powerfully than a standard one, stopping the chain faster and more effectively.

Currently, only STIHL offers the Quick-stop Super additional braking system for chainsaws.

This Quick-stop feature depends on several factors, including its design, size, and the materials used in its making.

A chain brake with a larger brake band and a more robust spring will be more abrupt, as it can apply more force to stop the chain. A brake band made of high-quality materials, such as heat-treated steel or carbon fiber, can also improve the effectiveness of the brake.

In manual chainsaws, the positioning of the chain brake on the chainsaw can also affect its quickness. A brake closer to the chainsaw’s front can engage faster and with greater force, resulting in a more aggressive chain stop.

Learn More: How to Reset Chain Brake on a Husqvarna Chainsaw?

Common Issues with Chain Brakes Working

Chain brakes are generally effective and rarely experience issues, but at the end of the day, it’s also a machine and can malfunction. Here are some common issues that can arise with chain brake workings:

  • Improper use of chainsaws always turns out to be the most occurring reason for chain brake malfunction. When someone uses only the tip of the saw for cutting or holds the chainsaw above his shoulder height, it can cause frequent kickbacks. This results in chain brakes wearing out more quickly.
  • A greasy lever can also cause the chain brake not to work when needed. When we fill the oil reservoir of chainsaws, we usually cover their whole body with oil. If you forget to clean the lever, your hand may end up slipping over it instead of pulling it. So, make sure your chain brake lever is dry and pullable.
  • Loose Spring is another reason for chain brake malfunction. Spring is the most important component of the chain brake system. It does all the essential work of keeping the band tight and firm.

If the spring is broken or loose, it may not apply enough tension to the brake band, reducing stopping power and increasing band wear and tear. This can also result in the chain brake engaging unexpectedly or failing to engage at all.

  • A chainsaw’s brake band may wear out or suffer damage over time. This reduces its ability to generate enough friction to stop the chain. As a result, it’s essential to inspect the brake band on a regular basis and replace it if it shows signs of wear or damage.

Read More: How Much is a Cord of Wood?

Frequently Asked Questions About Chainsaw Chain Brakes

What does a chainsaw brake do?

A chainsaw brake is a safety feature that stops the rotation of the cutting chain in the event of a kickback or any sudden movement, which could cause injury to the user. Manual chain brakes require you to pull the lever, while inertia chain brakes are automatic.

How to activate a chainsaw brake on a chainsaw?

The chain brake on a chainsaw activates by pulling a lever on the top of the front hand guard. This tightens the brake band around the clutch drum of the chainsaw, creating friction that eventually stops the chain rotation.

Should you start a chainsaw with a chain brake on?

No, you should not start a chainsaw with the chain brake on. The chain brake is a safety feature that stops the chain from rotating when the chainsaw is not in use or during kickback.

If the chain brake is already on, the chainsaw’s engine will start, but the chain will not move, which can cause the chainsaw to jerk and may harm the operator.

How does a chainsaw brake work on a Stihl chainsaw?

Stihl chainsaw uses a manual chain brake system. It consists of a brake band that encircles the clutch drum. When the brake is on, the band wraps itself tightly around the clutch drum, stopping the chain’s rotation.

Is it bad to rev a chainsaw with a brake on?

You should not rev a chainsaw with the brake on because it can cause damage to the engine and clutch system.

When the chainsaw brake is pulled, it stops the chain from rotating, which puts extra strain on the engine and clutch. This can cause the engine to overheat or the clutch to wear prematurely, leading to costly repairs.

When Should A Chainsaw Chain Brake Be Used?

A chainsaw chain brake should be used when there is a risk of kickback, such as during startup and shutdown, breaks or pauses, moving from one cutting area to another, or encountering an obstacle, to prevent the chain from rotating and potentially causing injury.

Final Takeaways

And here you go, buddy!

Kickbacks are scary, especially when dealing with unfamiliar projects. Who knows when the chain encounters a tough branch and shakes you from the core?

So, understanding how a chain brake works and using it correctly can help ensure a safe and effective chainsaw operation.

Moreover, there are additional steps you can take to reduce the risk of kickback while using a chainsaw. This includes using a sharp chain, avoiding cutting with the chainsaw’s tip, and properly maintaining and adjusting the chainsaw.

Patrick McMann