A chainsaw is a dangerous device, and in the hands of an inexperienced user, it can be doubly harmful.
In the past, chainsaws were sold only to those who worked with timber by trade (and before that, chainsaws were used in childbirth!). Still, more than three million chainsaws are purchased in the United States annually for various purposes.
Even though they come equipped with safety features such as kickback protection and chain brakes, they are amongst the most dangerous pieces of equipment and can pose life-threatening injuries if not used correctly or as intended.
Below, we’ll explain chainsaw kickback, the kickback zone, the causes of kickback, preventive measures, and how to avoid kickbacks altogether.
Chainsaw Kickback
Chainsaw kickback is an expression used to describe the guide bar’s sudden and lightning-fast upward motion. The video above provides an example.
The CSA (Canadian Standards Association) describes kickback as, ‘the rapid upward motion of the guide bar that can occur when the saw chain, near the nose (tip) of the top area of the guide bar, contacts an object such as a log or branch (rotational kickback), or the backward movement that can occur when the wood closes in and pinches the saw chain in the cut (pinch kickback).’
This can be hazardous and is one of the most common causes of chainsaw accidents. We’ll examine the different types of kickbacks that can occur and what you need to be wary of.
1. Linear Kickback
This occurs when the saw chain at the other end of the bar is pinched by the object that is being cut.
Therefore, if the chain gets pinched or closed on either side of the object at any point, the chainsaw will be pushed back at full throttle due to the excess power.
The bottom line is do not allow the chain to get pinched, and be extremely careful and alert.
2. Rotational Kickback
This is a dangerous one and also the most common.
It is the least controllable and is initiated when an object touches the nose or the guide bar’s tip, causing the saw to go haywire and be “kicked” back towards you with maximum force. This nose or tip is called the kickback zone, as discussed below.
When the cutting angles of the teeth angle back, they tend to run on the wood rather than cutting into it. The teeth grinding onto the wood instead of into it forces the bar’s tip upwards towards you.
It will catch you by surprise, and you will lose control of it and get a kickback, all in a split second.
3. Pull-In Kickback
If the saw you are using hits a piece of wood or a nail on the other end, the saw will be jerked forward and away from your grip.
The Kickback Zone
Chainsaw kickbacks mainly occur in the kickback zone on the saw blade.
This zone refers to the top of the chainsaw bar’s tip. If you use this point to cut, the blade will get pinched on the wood, causing the dreaded kickback.
Remember that the larger the guide bar’s nose, the higher the probability of chainsaw kickback.
The zone is considered a high-risk area, and you are advised not to use that part of the bar while cutting or sawing, as doing this will exponentially increase the chances of experiencing a kickback.
What Causes Chainsaw Kickback?
Most commonly, kickback occurs when the chain gets pinched on something, like a piece of wood.
Since the saw can’t handle a large piece of wood when it hits the cutting tooth, the chain stops entirely, leaving the power to go nowhere else.
It’s often easy to forget that even if the chainsaw chain is stuck, the engine is continuously running, and the power is still there. Consequently, according to Newton’s third law of motion (which states that for every action, there is an equal and opposite reaction), the kickback is initiated.
The more the chainsaw gets stuck, the more brutal and dangerous the kickback.
Under normal circumstances, the chainsaw’s individual teeth take off little pieces of wood at a time. However, this takes place rapidly while operating the chainsaw, which makes for a clean cut. The depth gauge decides each cut is depth, allowing a small piece of wood to be cut at a time.
Usually, chainsaws are made so that the depth gauge allows for approximately 0.018 inches to 0.030 inches of wood to be cut with each different cut. In the kickback zone, the chain’s alignment is such that more wood is cut than advised below the cutting tooth.
Three main situations can trigger a kickback:
- When the moving chain at the guide bar’s tip hits an object, as mentioned above
- When the wood closes, pinching the saw chain in the middle of cutting
- Pull-in kickback
All of these incidents cause the guide bar to inadvertently kick back, which causes the operator to lose control of the saw and result in serious injuries.
Other than the scenarios listed above, there are also several minor issues (which alone or in combination with another issue) can drastically increase the chances of a chainsaw kickback.
These are:
- Dull chain
- Neglected or improper chain saw maintenance
- Loose saw chain tension
- Incorrectly fitted parts
- Broken or cracked chain components
- Loose rivets
- Wrongly sharpened chain angle
How to Prepare for Kickback
You may be familiar with the expression, ‘prevention is better than cure.’
This is highly applicable when handling a chainsaw because once the kickback occurs, it is impossible to do anything about it.
Being prepared ahead of time is the best option.
You must wear the right gear. Helmets with a visor should be the primary choice because when a kickback occurs, the head is one of the prime targets for injury.
Another essential piece of equipment is thick trousers or good chainsaw chaps. Chainsaw chaps are preferable because they are chainsaw resistant and specially designed to protect the left side of your leg, another prime target for a kickback.
Other protective equipment should include:
- Jacket
- Thick leather gloves
- Earplugs
- Heavy boots (i.e., logging boots)
Take the advice to obtain and invest in proper protective equipment seriously. It could be what saves you from a life-or-death situation.
Avoid Kickback
There are many ways to avoid a potential chainsaw kickback.
Here are some of the best rules to avoid losing your thumb.
Read The Manual
Reading the instruction manual should be your first order of business, especially if you are not an experienced chainsaw operator.
The manual will provide all the information you need to use the chainsaw correctly and, more importantly, safely.
Prepare The Saw
Checking on the chainsaw before starting work is always a good idea. Teeth that are sharpened perfectly will cut more efficiently, smoothly, and safely.
Check the air filter, spark plug, muffler, and all other components to ensure that they are working properly. This will improve the engine’s performance and prevent possible kickbacks. Also, keep the instruction manual handy and consult it while making adjustments to the engine or the chain.
Proper chain tension will help in sustaining a long chain life and will cut more precisely, as well. A too-loose chain will be inclined to derail, sway about, and could be a hazard in itself.
Alternatively, a chain that is too tight will prematurely become old and blunt. Remember that all chains stretch with use, and checking and readjusting are essential every time you use one.
Lubricating it properly with oil will help maintain the correct tension. Check the oil as often as possible, and refill it if needed while carefully following the directions.
Check The Chain Brake
The chain brake is the most vital part of a chainsaw. It is specially designed to stop the saw chain by applying a brake. It’s incredibly useful if a kickback occurs, as it can lessen the possibility of serious injury.
The chain brake stops the cutting chain and is also used to stop or prevent the chain from accidentally picking up speed while you are switching cutting positions. Most chainsaws come with two types of braking systems: one is an inertia braking system, and the other is a mechanical braking system.
Some manufacturers have also developed a third braking system, such as Husqvarna’s TrioBrake, which has a second mechanical brake at the rear end of the saw.
When a kickback occurs, the chain brake can be used to halt the rotating chain. While being struck by a stopped chain isn’t ideal, it is far better than being hit by a full-speed rotating chain.
Low Kickback Chains
Modern chainsaws have safety features that efficiently reduce kickbacks.
These features include chain breaks (as discussed above), the bar tip guard, and low or reduced kickback chain and guide bars. For these features to work effectively, it’s crucial to double-check and ensure that the chainsaw is assembled correctly and that all the parts are attached and function properly.
Low-profile chains or semi-chisel chains are a good fit for beginners, as they are specifically designed to have less kickback.
Keep Chain Sharp
Using a dull chain increases the risk of causing a kickback, as the teeth cannot slice through the wood, which causes the chain to get stuck and cause a kickback.
Watch The Kickback Zone
The area to avoid is the chainsaw bar’s nose (as it is the kickback zone). Be alert and use the correct part of the chainsaw to ensure there are no kickbacks.
Maintain A Solid Grip
Make sure to have a good grip on the chainsaw and ensure your hands are not slippery. The right hand should always hold the rear handle, and the left hand should have a firm hold on the front handle. A good pair of chainsaw gloves can help.
Operate Chainsaw Correctly
The ANSI (American National Standards Institute) instructs that “a chainsaw shall be operated with the left hand and thumb gripped firmly around the forward handle and the right hand and thumb gripped firmly around the rear handle.”
The standard also advised the user to be in a steady and firm body position before starting the chain saw.
Check Your Surroundings
Always check your surroundings to see any obstacles or barriers in the area where you are cutting.
- Pay attention to the bar’s nose
- Constantly watch the nose of the bar and do not let it make contact with any object, such as a branch or a piece of wood.
- Cut at engine speed
This is where the chain is most effective, and, thankfully, there is less chance of a kickback occurring.
Use Suitable Chains
Use chains that are suitable for your cutting needs during that particular time.
This is because there are various chain types; some chains are lighter, and their pitches differ according to size.
Work On The Correct Side
Work on the left side of anything you cut, as close to the chainsaw as possible, as it gives you complete control.
Stay Alert
Pieces of wood can jam in the chain and be thrown into your face, causing you to lose control of the saw.
Obviously, this is one of the worst-case scenarios, so be extremely alert.
Avoiding Chainsaw Kickback
If you are a beginner when it comes to using chainsaws (or happened to have forgotten their potentially harmful mishaps), the above is a handy and perhaps life-saving guide.
The obvious end goal is to know what a kickback is, how it happens, and why it can keep you out of harm’s way. It’s also imperative to take preventive measures and obtain protective gear to ensure your safety.
Ultimately, it all comes down to properly maintaining and taking care of your chainsaw. Knowing how to use the saw effectively is key. Having this information in your toolbox of knowledge could be the best tool you’ve ever had.
Think about attending a chainsaw course to familiarize yourself with the tool better, and make sure you learn how to keep your chainsaw clean for the safest operation.
I find that you always hear people who don’t know much about chainsaws talking about kickback but it doesn’t happen seriously all that often. Obviously it only needs to get you once, but it’s not something we need to be overly anxious about. Hold on to your saw and remain attentive and you’ll be right.
Yeah, serious events are fairly rare thankfully. However, it depends on the wood you’re working with. I was speaking with an arborist today who said his saw kicked back 15 times today. He was taking down some large macrocarpa and it would happen on those smaller limbs.