What Makes A Chainsaw Chain Low Kickback? (Explained)
Chainsaw kickback is one of the most common and dangerous issues faced by chainsaw users. Kickback occurs when the moving chainsaw chain near the upper quadrant of the bar nose contacts a solid object or binds, causing the bar to move suddenly upward and backward toward the operator.
This rapid kickback motion can cause the operator to lose control of the saw, potentially resulting in dangerous and even fatal contact injuries. Understanding what causes kickback and how to choose chains and operate saws to reduce it is crucial for safe chainsaw operation.
What Causes Chainsaw Kickback
There are two main situations that typically cause kickback:
Pinching the Chain Along the Top of the Bar
This dangerous pinch kickback occurs when the wood closes in and pinches the chain along the top of the guide bar. This often happens when making bore cuts, plunge cuts, or incorrect upper cuts.
The pinched chain pulls the saw forward and rotates the bar upward toward the operator. This can occur suddenly with little warning.
Tip Contact
Tip contact kickback occurs when the moving chain near the upper quadrant of the bar nose contacts a solid object like a log or branch hidden within the wood.
This contact pulls the chain and kicks the bar upward toward the operator. Tip contact is especially dangerous because it can happen suddenly when least expected.
Factors that Influence Chainsaw Kickback
Several factors can influence the likelihood and severity of chainsaw kickback:
Chain Type and Design
Some chains are specifically designed to reduce kickback. We’ll cover features like depth gauges, guard links, and low kickback chain in more detail shortly.
Maintenance and Condition
Well-maintained chains with sharp cutters tend to kickback less. Blunt or damaged cutters can increase binding and kickback risk.
Saw Size and Power
More powerful chainsaws with longer bars can deliver more severe kickback force. Their extra momentum makes uncontrolled upward movements more dangerous.
Use of Safety Devices
Safety features like chain brakes and front hand guards can reduce kickback injuries. Keeping both hands firmly gripped on the chainsaw also gives you more control.
Operator Technique
Proper cutting technique is crucial. Avoid situations known to increase pinching and kickback risk. Also anticipate and prepare to control the saw if kickback does occur unexpectedly.
Design Features that Reduce Kickback
Chainsaw and chain manufacturers have developed various design features to help reduce dangerous kickback:
Low Kickback Chains
These have specialized depth gauge and guard link geometry designed to minimize tip contact and nose kickback. We’ll examine these key features next:
Depth Gauges
The depth gauges are the small metal tabs ahead of each cutter that regulate the depth of cut. Low kickback chains have more precisely filed depth gauges that create a shallower top plate angle.
This reduced angle allows the cutter to gradually contact and enter the wood rather than aggressively boring in. This reduces sudden grabbing and rotational kickback forces.
Diagram showing top plate filing angle
Reduced top plate angle of depth gauges minimizes grab and kickback
Guard Links
Guard links are located along the sides of each low kickback drive link. They deflect wood away from the chain if the cutter nose contacts material along the top of the bar. This prevents the chain from pinching or boring in too deeply.
Diagram showing guard link kickback protection
Guard links deflect wood away from the chain
Tip Radius
Some chains have a larger, smoother radius at the front corner of each cutter. This increased tip radius reduces the likelihood of aggressive boring or sudden wood contact by allowing more gradual engagement with the wood.
Chain Brakes
Many chainsaws now include inertial chain brakes that stop the chain during sudden kickback motion. Either a mechanical device or centrifugal force engages the brake.
This brake acts within a split second to stop the chain after rapid acceleration from kickback. Chain brakes can greatly reduce kickback injuries when properly maintained.
Diagram showing chain brake mechanism
Chain brakes engage after sudden kickback motion
Low Kickback Bars
These have a more gently curving bar nose and elbow to allow a smoother transition into the cut. This allows the chain to begin cutting more gradually to reduce grab.
Many modern guide bars now incorporate low kickback features into their design.
Front Hand Guard
A prominent hand guard extending below the front handle provides leverage should kickback occur.
This gives extra protection and control compared to rear handles only. Guards help operators resist the upward motion during sudden kickback.
Kickback Reduction Tips
While following design features like those above will reduce kickback risks, appropriate chainsaw handling technique is most important. Here are key operational tips to minimize unexpected kickback:
Use Low Kickback and Properly Maintained Chains
Choose chains with low kickback geometry and ensure depth gauges are filed properly. Maintain the specified top plate filing angle.
Keep Chain Sharp
A sharp chain is less likely to bind in wood and initiate kickback. Monitor chain dullness and file or replace as needed.
Avoid Situations Where Material Can Pinch Chain
Pay extra caution making bore cuts, plunge cuts into existing wood, and incorrect upper cuts. Avoid letting the wood close down and pinch along the bar’s top quadrant.
Start Cuts Carefully
Begin each cut with the lower bar quadrant to create an opening for the upper portion. Never start a plunge cut with the nose. Let the chain accelerate to speed before contacting wood.
Correct cut initiation with lower bar quadrant
Always start cuts with lower section first
Use Firm Grip With Thumbs Wrapped Around Handles
Wrap thumbs over the front handle and grip firmly with both hands. This lets you resist kickback forces. Don’t let go!
Stand to Side of Cutting Plane
Standing aligned behind or in front of the bar can put you directly in line for kickback rotation. Always cut from the side so potential kickback drives the saw away rather than toward you.
Operator standing to side of cutting plane
Stand offset from the cutting plane
Maintain Full Saw Control
If kickback starts, hold on firmly and resist the upward motion. Don’t let go of the chainsaw. Immediately release throttle so chain brake can activate.
Wear Safety Equipment
Use chainsaw chaps, steel-toe boots, hard hat, and gloves. Safety gear protects body areas should a kickback injury occur.
Kickback Troubleshooting
Here are some common kickback questions and troubleshooting tips:
Frequently Asked Questions
My chainsaw keeps experiencing kickback. What should I check?
Start by inspecting chain condition. A dull or damaged chain can increase kickback risk. The depth gauges may also be incorrectly filed. Verify they match the specified top plate angle for the chain. Also check for issues like a loose bar, damaged sprocket, or binding clutch.
What maintenance helps reduce kickback?
Sharpen the chain regularly to keep cutters sharp and maintain depth gauge angles. Make sure the bar rails are straight and free of burrs. Lubricate the bar sprocket tip and chain regularly. Also check the clutch and chain brake for wear and damage.
Should I switch to a different chain design or brand?
If kickback problems persist after ensuring correct operation and maintenance, switch to a low kickback chain design from a reputable brand. This usually reduces the issues. Match to the correct bar and saw specifications.
I’m new to chainsaws. What basic safety steps should I take regarding kickback?
Always use two hands and grip the saw firmly with thumbs wrapped around handles. Stand to the side so kickback rotates the saw away from you. Start cuts with the lower section. Maintain full control if kickback occurs, holding firmly rather than letting go. Wear protective clothing.
Troubleshooting Tips
Here are some troubleshooting tips if your chainsaw experiences frequent or severe kickback:
- Check chain condition and top plate filing angles
- Ensure bar rails are straight and sprocket tip is clean
- Examine clutch and chain brake for damage
- Try replacing with a low kickback chain
- Use proper grip and body positioning when cutting
- Consider a chain brake upgrade if your saw doesn’t have one
Conclusion
Chainsaw kickback is a dangerous phenomenon that occurs when the moving chain contacts an object or binds in the cut. Various design features like low kickback chain geometry, chain brakes, and front hand guards reduce kickback risks.
However, following safe operating technique is most important for controlling kickback forces. Always use proper grip, start cuts carefully, stand to the side, and maintain full control if kickback occurs.
With increased understanding of kickback causes and prevention, chainsaw users can more confidently operate their saws productively and safely.
Taking some time to learn helps ensure you stay in control and avoid dangerous kickbacks. Stay safe out there!
