What Causes a Chainsaw to Kick Back (5 Pro Arborist Tips)

Here’s how to avoid chainsaw kickback and stay safe, plus five pro arborist tips that will change how you work with your saw.

I’ve spent years in the woods, felling trees, limbing branches, and processing firewood. And if there’s one thing I’ve learned, it’s that respecting a chainsaw is paramount. Kickback is one of the most dangerous situations you can encounter while operating a chainsaw. It’s sudden, violent, and can cause serious injury. That’s why understanding what causes it and how to prevent it is absolutely crucial, whether you’re a seasoned pro or just starting out. In this article, I’m going to share my experience and knowledge to help you avoid chainsaw kickback and stay safe while working.

Understanding Chainsaw Kickback: A Deep Dive

Kickback happens when the upper quadrant of the chainsaw bar’s tip, known as the “kickback zone,” strikes a solid object or is pinched. This causes the saw to rapidly thrust backward and upward towards the operator. The force can be immense, and the consequences devastating.

What is the “Kickback Zone”?

Imagine the tip of your chainsaw bar. The upper quarter, usually marked on the bar itself, is the kickback zone. This area is the most susceptible to causing kickback. Contact with this area needs to be avoided.

Types of Kickback

There are primarily two types of kickback:

• Rotational Kickback: This is the most common type. It occurs when the chain in the kickback zone catches on an object, causing the saw to rotate back towards the operator.
• Pinch Kickback: This happens when the wood closes in on the chain, pinching it and forcing the saw backward. This can happen on the top or the bottom of the bar.

Factors Increasing Kickback Risk

Several factors can increase your risk of experiencing kickback:

• Improper Chain Tension: A loose chain is more likely to bind and kick back.
• Dull Chain: A dull chain requires more force to cut, increasing the likelihood of it catching and kicking back.
• Cutting Above Shoulder Height: This position makes it difficult to control the saw and react to kickback.
• Cutting with the Tip: Using the tip of the bar for plunge cuts or boring increases the chance of hitting a hidden object and causing kickback.
• Cutting Green Wood: Green wood, especially certain species, can be very springy and unpredictable, increasing the risk of pinch kickback.

5 Pro Arborist Tips to Prevent Chainsaw Kickback

Now, let’s get to the core of the matter: how to prevent kickback. These are the techniques I’ve honed over years of working with chainsaws.

1. Master the Bore Cut (and Know When to Use It)

The bore cut, or plunge cut, is an essential technique for felling trees and removing limbs, but it can also be a major source of kickback if not performed correctly.

The Correct Bore Cut Technique:

1. Stance is Key: Position yourself firmly and slightly to the side of the tree. Never stand directly behind the saw.
2. Controlled Entry: With the bottom edge of the bar, carefully bore into the wood. Use the lower part of the bar to cut and avoid the kickback zone.
3. Watch for Pinching: Be vigilant for any signs of the bar pinching. If you feel resistance, stop immediately and re-evaluate.
4. Create a Hinge: The bore cut is often used to create a hinge when felling a tree. This hinge controls the direction of the fall.
5. Don’t Over-Bore: Avoid over-boring, which can weaken the hinge and lead to unpredictable tree movement.

When to Use the Bore Cut:

• Felling Trees: Creating a hinge to control the direction of the fall.
• Removing Limbs: Relieving pressure on limbs before cutting them completely.
• Freeing a Pinch: When the bar is pinched, a bore cut can sometimes relieve the pressure.

My Personal Experience: I remember one instance where I was felling a large oak tree. I meticulously planned my bore cut to create the perfect hinge, but as I was boring, I felt a sudden increase in pressure. I immediately stopped, and upon closer inspection, I realized the tree was leaning slightly more than I had anticipated. Had I continued, the tree could have twisted and pinched the bar, potentially leading to a dangerous kickback situation. This experience reinforced the importance of constant vigilance and the ability to react quickly.

Data and Insights: In my projects, I’ve noticed that using a bore cut with a bar length appropriate for the tree’s diameter reduces the risk of pinching. For example, when felling trees with a diameter of 24 inches, I use a chainsaw with at least an 18-inch bar. This allows for a more controlled bore cut without overextending the bar. Also, I typically use a chainsaw with a chain brake, which can stop the chain instantly in case of kickback.

2. Always Use the Chain Brake

The chain brake is your first line of defense against kickback. It’s a simple but incredibly effective safety device.

How the Chain Brake Works:

The chain brake is a lever located in front of the top handle of the chainsaw. When activated, it stops the chain almost instantly. It is activated by pushing the lever forward, usually with your wrist or hand.

When to Use the Chain Brake:

• Before Starting the Saw: Always engage the chain brake before starting the saw.
• When Moving Between Cuts: Engage the chain brake when moving between cuts, even if it’s just a short distance.
• When Setting the Saw Down: Always engage the chain brake before setting the saw down.
• Any Time the Saw is Not Actively Cutting: If you’re not actively cutting, the chain brake should be engaged.

Maintaining Your Chain Brake:

• Regular Inspection: Check the chain brake regularly to ensure it’s functioning properly.
• Professional Service: Have the chain brake serviced by a qualified technician if you suspect any issues.

Personal Story: Early in my career, I was limbing a fallen tree. I became complacent and didn’t engage the chain brake when moving between cuts. I tripped over a branch, and the saw lurched forward. Luckily, my hand instinctively engaged the chain brake, preventing a potentially serious injury. This incident was a stark reminder of the importance of always using the chain brake, no matter how routine the task may seem.

Data and Insights: From my observations, I noticed that arborists who religiously use the chain brake experience fewer chainsaw-related injuries. It’s such a simple action that can prevent a lot of accidents. I recommend checking the brake band wear as well since that can affect performance over time.

3. Maintain Proper Chain Tension

Proper chain tension is crucial for safe and efficient chainsaw operation. A chain that’s too loose is more likely to derail and kick back, while a chain that’s too tight can overheat and break.

Checking Chain Tension:

1. Cool Down: Allow the chain to cool down before checking the tension. A hot chain will be tighter than a cold chain.
2. Lift the Chain: Using a gloved hand, lift the chain away from the bar in the middle of the bar’s underside.
3. Proper Tension: The chain should lift slightly away from the bar, but the drive links (the parts of the chain that fit into the bar’s groove) should remain in the groove.
4. Adjust if Necessary: If the chain is too loose or too tight, adjust it according to the manufacturer’s instructions.

Adjusting Chain Tension:

1. Loosen the Bar Nuts: Loosen the bar nuts that hold the bar in place.
2. Adjust the Tensioning Screw: Locate the tensioning screw, usually on the side of the saw. Turn the screw to adjust the chain tension.
3. Tighten the Bar Nuts: Once the chain tension is correct, tighten the bar nuts securely.

Common Mistakes to Avoid:

• Over-Tightening: Over-tightening the chain can cause excessive wear on the bar and chain, and can even lead to the chain breaking.
• Ignoring Tension Changes: Chain tension can change as the saw heats up or cools down. Check the tension regularly and adjust as needed.

Case Study: I once worked on a project where we were cutting a large quantity of firewood. One of the workers consistently neglected to check the chain tension on his saw. As a result, the chain derailed several times, and on one occasion, it nearly caused a kickback. After I showed him how to properly check and adjust the chain tension, he experienced no further problems. This case study highlights the importance of regular chain maintenance.

Data and Insights: I’ve found that a properly tensioned chain not only reduces the risk of kickback but also improves cutting efficiency. A chain that’s too loose will vibrate and chatter, while a chain that’s too tight will create excessive friction and heat. A properly tensioned chain will cut smoothly and efficiently.

4. Sharpen Your Chain Regularly

A dull chain is a dangerous chain. It requires more force to cut, increasing the likelihood of kickback and other accidents.

Signs of a Dull Chain:

• Sawdust Instead of Chips: A sharp chain produces long, clean chips. A dull chain produces fine sawdust.
• Difficulty Starting Cuts: A dull chain will struggle to bite into the wood.
• Excessive Vibration: A dull chain will vibrate more than a sharp chain.
• Burning Smell: A dull chain will create excessive friction and heat, which can produce a burning smell.

Sharpening Techniques:

1. Use the Correct File: Use a chainsaw file that is the correct size and shape for your chain.
2. Maintain the Correct Angle: Hold the file at the correct angle, usually marked on the file guide.
3. File Each Cutter Evenly: File each cutter evenly to maintain a consistent cutting edge.
4. Lower the Depth Gauges: After sharpening the cutters, lower the depth gauges (the small metal tabs in front of each cutter) to the recommended height.

Tools for Chain Sharpening:

• Chainsaw File: A round file for sharpening the cutters.
• File Guide: A tool to help maintain the correct filing angle.
• Depth Gauge Tool: A tool for lowering the depth gauges.
• Chain Vise: A vise to hold the chain securely while sharpening.

Unique Insight: I recommend using a chainsaw chain sharpener. These tools can sharpen the chain more precisely and consistently than manual filing.

Personal Story: I once attempted to fell a tree with a severely dull chain. The saw struggled to cut, and I had to apply excessive force. The saw eventually kicked back, throwing me off balance. I was lucky to escape with only minor bruises, but it was a valuable lesson in the importance of maintaining a sharp chain.

Data and Insights: I’ve observed that arborists who sharpen their chains regularly experience fewer kickback incidents and have a higher overall productivity. A sharp chain cuts more efficiently, reducing the amount of time and effort required to complete a task.

5. Maintain a Safe Working Stance and Avoid Overreaching

Your body position and stance play a crucial role in preventing kickback and maintaining control of the chainsaw.

Proper Stance:

• Feet Shoulder-Width Apart: This provides a stable base of support.
• Slightly Bent Knees: This allows you to absorb shocks and maintain balance.
• Firm Grip: Grip the saw firmly with both hands, wrapping your thumbs around the handles.
• Keep the Saw Close to Your Body: This gives you more control and reduces the risk of overreaching.

Avoiding Overreaching:

• Move Your Feet: Instead of reaching, move your feet to maintain a comfortable and safe working distance.
• Don’t Cut Above Shoulder Height: Cutting above shoulder height makes it difficult to control the saw and react to kickback.
• Use a Ladder or Platform: If you need to cut above shoulder height, use a ladder or platform to maintain a safe working position.

Cutting Techniques:

• Cut on Your Strong Side: Whenever possible, cut on your strong side. This gives you more control and reduces the risk of kickback.
• Avoid Cutting with the Tip: Avoid cutting with the tip of the bar, which is the most susceptible to kickback.
• Be Aware of Your Surroundings: Be aware of your surroundings and avoid cutting near obstacles that could cause the saw to kick back.

Case Study: I was once working with a crew clearing brush along a roadside. One of the workers was cutting branches that were slightly out of his reach. He lost his balance and the saw kicked back, striking him in the leg. Fortunately, he was wearing chaps, which prevented a serious injury. This incident highlighted the importance of maintaining a safe working stance and avoiding overreaching.

Data and Insights: I’ve noticed that arborists who prioritize proper body mechanics and avoid overreaching experience fewer injuries and have a higher overall level of safety. A stable and balanced stance allows you to react more quickly to unexpected events, such as kickback.

Beyond the Basics: Advanced Chainsaw Safety

While the five tips above are essential, there are other important considerations for advanced chainsaw safety.

Personal Protective Equipment (PPE)

Wearing the proper PPE is non-negotiable when operating a chainsaw.

• Chainsaw Chaps: These protect your legs from cuts.
• Safety Glasses or Face Shield: These protect your eyes from flying debris.
• Hearing Protection: Chainsaws are loud and can cause hearing damage.
• Gloves: These provide a better grip and protect your hands.
• Steel-Toed Boots: These protect your feet from falling objects.
• Helmet: Protects your head from falling debris.

Chainsaw Selection

Choosing the right chainsaw for the job is important.

• Bar Length: Select a bar length that is appropriate for the size of the trees you will be cutting.
• Power: Choose a saw with enough power to handle the tasks you will be performing.
• Weight: Consider the weight of the saw, especially if you will be using it for extended periods.
• Anti-Vibration Features: Look for a saw with anti-vibration features to reduce fatigue.

Chainsaw Maintenance

Regular maintenance is essential for safe and efficient chainsaw operation.

• Clean the Air Filter: A dirty air filter can reduce engine performance and increase the risk of overheating.
• Check the Spark Plug: A faulty spark plug can cause the saw to run poorly.
• Lubricate the Bar and Chain: Proper lubrication is essential for reducing friction and wear.
• Inspect the Sprocket: A worn sprocket can cause the chain to derail.

Understanding Wood Types

Different types of wood behave differently when cut.

• Green Wood: Green wood is freshly cut wood that has a high moisture content. It can be heavier and more difficult to cut than seasoned wood. It is also more prone to pinching the bar.
• Seasoned Wood: Seasoned wood has been dried and has a lower moisture content. It is easier to cut than green wood and less prone to pinching.
• Hardwoods: Hardwoods are generally denser and more difficult to cut than softwoods.
• Softwoods: Softwoods are generally less dense and easier to cut than hardwoods.

Felling Techniques

Felling a tree safely requires careful planning and execution.

1. Assess the Tree: Assess the tree for lean, wind direction, and any potential hazards.
2. Plan the Escape Route: Plan an escape route that is clear of obstacles and at a 45-degree angle away from the direction of the fall.
3. Make the Notch Cut: Make a notch cut on the side of the tree facing the direction of the fall.
4. Make the Back Cut: Make a back cut on the opposite side of the tree, leaving a hinge of wood to control the direction of the fall.
5. Warn Others: Warn others in the area that you are about to fell a tree.

Case Study: Preventing Kickback in a Firewood Processing Operation

I once consulted with a small firewood processing operation that was experiencing a high rate of kickback incidents. After observing their operation, I identified several areas for improvement.

• Chain Maintenance: The workers were not sharpening their chains regularly, and many of the chains were dull. I implemented a chain sharpening program and trained the workers on proper sharpening techniques.
• Cutting Techniques: The workers were using improper cutting techniques, such as cutting with the tip of the bar and overreaching. I provided training on proper cutting techniques and emphasized the importance of maintaining a safe working stance.
• PPE: Some of the workers were not wearing the proper PPE, such as chaps and safety glasses. I made sure that all workers were wearing the required PPE.
• Chainsaw Selection: The workers were using chainsaws that were too large and powerful for the tasks they were performing. I recommended that they use smaller, lighter chainsaws.

As a result of these changes, the firewood processing operation experienced a significant reduction in kickback incidents and an improvement in overall safety.

Practical Next Steps

Now that you have a better understanding of what causes chainsaw kickback and how to prevent it, here are some practical next steps you can take:

1. Review Your Chainsaw Safety Manual: Familiarize yourself with the safety features and operating procedures for your chainsaw.
2. Practice Safe Cutting Techniques: Practice safe cutting techniques in a controlled environment, such as a log pile or a designated training area.
3. Attend a Chainsaw Safety Course: Consider attending a chainsaw safety course to learn from experienced instructors.
4. Inspect Your Chainsaw Regularly: Inspect your chainsaw regularly for any signs of damage or wear.
5. Always Wear PPE: Always wear the proper PPE when operating a chainsaw.

Strategic Insights

Beyond the tactical tips, here are some strategic insights to consider:

• Safety Culture: Create a safety culture in your workplace or among your friends who use chainsaws. Encourage open communication about safety concerns and reward safe behavior.
• Continuous Improvement: Continuously look for ways to improve your chainsaw safety practices. Stay up-to-date on the latest safety standards and techniques.
• Training and Education: Invest in training and education for yourself and your employees. A well-trained workforce is a safe workforce.

Conclusion

Chainsaw kickback is a serious hazard that can cause serious injury. By understanding what causes kickback and following the five pro arborist tips outlined in this article, you can significantly reduce your risk of experiencing this dangerous event. Remember to always prioritize safety and to never become complacent when operating a chainsaw.

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