Using a chain saw
Chain saws are the perfect tool for cutting up fallen trees and large branches. But figuring out where to start and how to go about the job safely is a challenge. We enlisted a chain saw expert to walk us through the process of cutting up a large fallen tree.
We'll show you what we learned, including techniques for removing branches and cutting up the trunk. Of course, safety is the most important consideration when you're using a chain saw. See “Safety Tips” for key precautions I've taken to heart. But in addition to these tips, be sure to read and follow the safety precautions listed in your chain saw owner's manual.
Cut with the top or bottom of the bar and chain, but avoid the kickback zone
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Kickback zone on a chainsaw
Avoid cutting with the “kickback zone” of the chainsaw bar. It can cause the saw to kick back toward you.
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Keep control of the chain saw while you’re cutting by using an encircling grip.
Cutting with the chain on the bottom of the bar is the most common and natural-feeling way to cut. The saw pulls slightly and is easy to control by maintaining a firm grip. Cutting from the underside of a branch requires you to cut with the top of the bar. This is a little unnerving at first because the saw pushes toward you. But it's safe as long as you're well braced and follow all other precautions.
However, there's one spot on the bar that you should carefully avoid. This spot, called the kickback zone, is the top half of the bar's tip. If the kickback zone comes in contact with something while the chain is moving, the saw will kick up and back toward you. That's why modern chain saws are equipped with a chain brake designed to stop the chain if a kickback occurs.
The most common chain saw injuries to the thigh and left arm can be virtually eliminated with just a few simple precautions. First, always wrap the thumb of your left hand around the front handle while you're cutting. This encircling grip keeps the saw under control in the event of a kickback.
Second, when you move from place to place with the saw running, even if it's only to the next branch, always remove your right hand from the back handle and carry the saw at your side with your left hand holding the front handle. Then if you trip or stumble, there's no way the saw's engine can accelerate and start the chain spinning.
The first step in chain saw safety is to wear the right
Put on your safety gear
Buy safety gear and wear it. Special chaps will often stop a moving chain and save your thigh. A helmet with a face screen and ear protection is a convenient way to keep head, eye and ear protection handy in one comfortable package. Wear steel-toed, cut-resistant boots and a long-sleeved shirt to protect
against the inevitable scratches. You'll find this gear at chain saw dealers.
Get a feel for your machine
Now that you're dressed, fill the saw with gas that's premixed with two-cycle
oil (see your owner's manual for
the proper mix for your chain saw).
Then fill the oil tank with bar and
chain oil. After the saw is filled, move
it at least 10 ft. away from the filling
area to a spot cleared of any ignitable
To start the saw, engage the chain
brake, turn on the
ignition switch, pull out the
choke (for a cold engine)
and lock on the fast idle.
With the saw sitting on
the ground, put the toe
of your right boot into
the back handle loop and
grasp the front handle with a
stiff left arm. Pull the starter handle
to fire up the engine. Push in the
choke and take it off fast idle, then pull the chain brake back toward the
front handle to release the chain brake
Get a feel for how your saw
responds to the throttle. Cut only
when you are in a comfortable, well-balanced
position with your feet
about shoulder-width apart. Stand to
one side of the saw, never directly
You'll feel different
forces when cutting. When
cutting with the bottom of
the bar, the saw will pull
you into the work. When
cutting with the top of the
bar (undercutting), the saw
will tend to push you away
from the work. This second force
is called a pushing chain. When cutting
with a pushing chain, brace the back handle of the saw or your arm
against your thigh to gain more control
of the saw and reduce fatigue.
Adjusting chain tension
Before starting, check the chain tension. Recheck it after
every hour or so of use, and adjust it if necessary. New chains stretch
and need to be checked after 20 minutes of use. Loose chains can fly off
the bar, causing serious injury. A loose chain also damages the drivers
BAR on the chain and prevents them from fitting back into the bar groove.
To make adjustments, loosen the bar
nuts that hold the bar.
Then lift the bar
screw until the
chain is snug
against the bar. The
tension is correct
when you can't lift
the chain drivers
free of the bar
groove but you can
still drag the chain
easily around the
bar with a gloved
hand. Retighten the
Plan a strategy for cutting up the tree
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Photo 1: Start cutting at the trunk, working toward the top
Cut off branches starting at the lower end of the trunk and working to the top. Whenever possible, rest the saw engine against the trunk and pivot the bar through the branch.
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Photo 2: Start cutting downward on branches under pressure.
Cut off branches that are under pressure by first cutting downward through one-third of the branch.
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Photo 3: Finish the cut by sawing upward.
Finish the cut by sawing upward to meet the first cut. Be prepared for the trunk to roll or drop.
Before you even start your saw, stand back and size up the situation. Think about how you'll cut each branch and what will happen when you do. Obviously branches facing up will fall.
Make sure the fall path is open. It's not so clear what will happen when you cut branches trapped under the fallen tree. They'll be under pressure, and in some cases removing them will cause the tree to drop. Even seasoned pros can't always predict how far the trunk will drop, or whether the tree will roll.
But you should always imagine the worst-case scenario and be prepared for it. Take a few minutes to clear a path behind you and to the side for a quick retreat. And always work with a partner so that if you become trapped or injured, you'll have someone to call for help.
Start by removing branches closest to the lower end of the trunk, and work toward the top of the tree. Whenever possible, stand on the uphill side of the tree. Photos 1 – 3 show techniques for removing branches from the top side of the trunk and branches under pressure.
Work from the left side of the trunk (as you face toward the top of the tree). This allows the safest and most efficient use of the chain saw because you can rest the side or bottom of the saw on the trunk and slice off the branches with a pivoting motion (Photo 1).
Cutting the tree trunk
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Photo 4: Start cutting downward in the trunk.
Cut trunks that are supported at both ends by making a downward cut one-third the diameter of the trunk.
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Photo 5: Cut upward to complete the cut
Finish by cutting up from underneath. Be prepared for one or both sides to drop.
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Photo 6: Take the pressure off the saw during a cut.
Stop the engine if the bar gets bound up or stuck. Then use a stout branch or 4x4 to lift the trunk and open the cut enough to remove the saw.
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Photo 7: Saw the trunk into firewood
Cut a log into 16-in. lengths for firewood by first sawing three-quarters of the way though the log. Then roll it over and complete the cuts.
As you cut branches out from under the trunk, it will settle to the ground. Finally the trunk will either rest entirely on the ground or hang suspended. If it's suspended, cut the trunk loose from the stump and carefully roll it to the ground. If you try to cut straight down through a trunk that's supported on both ends, the weight of the trunk will pinch the bar and stop the saw. Instead use the technique shown in Photos 4 and 5 to avoid binding.
The saw can also become pinched if you cut too far through a branch that supports the trunk. If this happens, stop the engine and use a stout branch as a lever to lift the trunk and free the saw (Photo 6).
After the trunk is free of branches and resting safely on the ground, cut it into manageable pieces, usually about 16 in. long for firewood. Start by cutting the trunk into 8-ft. long sections, a length short enough to roll over. Pick a spot on the trunk that has about a 3- to 6-in. gap under it. Otherwise your chain will hit the ground and quickly dull as you finish the cut.
Keep the bar parallel to the ground as you near the end of the cut, and finish with the bottom of the saw engine resting flat on the ground. That'll prevent the chain from accidentally hitting the dirt. Now use the process shown in Photo 7 to cut the longer sections into 16-in. lengths. With this method, you don't have to worry about your chain hitting the ground.
The Chain Saw Commandments
- Most chain saw injuries happen to
the thigh when the operator is carrying
a running saw. That's why chain
saw pants or chaps are important.
When transporting the saw less than
10 ft., carry it by the front handle
only. That way if you trip you won't
accidentally accelerate the saw and
cut your thigh. When moving more
than 10 ft., switch off the engine.
- Instruct everyone never to blindly
approach the operator. The noise of
the chain saw and the concentration
required may make the operator
oblivious to someone coming up
from behind to announce lunch.
- Never cut alone. If an accident
occurs, you'll need someone there to
administer first aid and summon
- Keep your cell phone with you for
- Understand the bar's kickback
zone and avoid getting into kickback
- Never cut above shoulder height.
- Work on the uphill side of trees so
they'll roll away from you instead of
- Use your chain brake! Whenever
you aren't cutting, the brake should be in the locked, or “On,” position.
- Start all cuts with a full throttle
before touching the wood.
- Never run a chain saw when
under the influence of drugs or alcohol.
When fatigued, rest!
- Protect your back. When trying to
move logs, use a lever or get help.
- Avoid touching the ground with
the chain because even a brief
encounter will severely dull the cutting
- Keep the chain sharp. A dull chain
is unsafe, hard on both the bar and
chain, and it overworks you and