There are a few things you must know to safely use a chainsaw. One of those is how to tighten the chain. A tight chain keeps the chain safely on the guide bar, it also allows your chainsaw to the cut at top efficiency.
There are some dangers with having a loose chain. I personally had a chain jump off my guide bar mid cut while I was up on a ladder. If not for the chain stop at the bottom of the chainsaw, I would have had a very bad day. I learned my lesson and now I am passing on some of what I’ve learned on to you.
In case you are wondering what a sacrificial chain stop is, the photo below has a close up of a small metal ‘J’ which is below the guide bar and chain. This will immediately stop your chain if it comes off the guide bar but will destroy the chain.
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How do you tighten a chain on a chainsaw?
To tighten a chainsaw you need to turn the tightening screw so the guide bar is pushed outward. You can do this with a flat head screw driver or use a chainsaw wrench tool like these. This stretches the chain out and ‘tightens’ the chain. You’ll need to tighten the chain until there is minimal wiggle in the chain.
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The photo below shows where you can find the chain tightening screw. Even though there is no visible screw, you’ll be able to fit a flat head screw driver and feel that it falls into place, then you can turn to tighten the chain.
You’ll know the chain is tight because you can barely pull the chain away from the guide bar. You can also test the tightness by releasing the chain break and trying to freely move the chain on the guide bar. If the chain is too hard to move back and forth then the chain is too tight and you’ll need to loosen the chain. Be sure to use gloves for this part. The Ranchworx gloves by Ironclad are my favorite.
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The photos below show the same chainsaw but the photo on the left shows a very loose chain. When the chain is pulled up you can see the drive links protrude past the level of the guide bar. The photo on the right is the same chain tightened and when pulling up the chain drive links barely become exposed. As a rule of thumb, you should not be able to expose the drive links on a properly tightened chainsaw.
Can you over tighten a chainsaw chain?
Yes, a chainsaw chain can be over tightened. The chainsaw will let you know if the chain is too tight because the chain will not run when you push on the gas. This is because the chain is so tight the engine cannot overcome the static friction between the chain and the guide bar.
You can also test the tightness by trying to manually move the chain with your gloved hand. Be sure the chain break is off, then grab the chain and slide it on the guide bar.
Why does my chain keep coming off my chainsaw?
A chainsaw chain is made to be tightened on the guide bar which it is running. If the chain is not tight then it is prone to jumping off the guide bar. This can be very dangerous and can even damage other components of your chainsaw. Follow the instructions of how to tighten your chainsaw chain for proper care of your chainsaw.
Why do you need to tighten a chainsaw?
Keeping a chain tight is important for several reasons. One is to maximize the efficiency of your chainsaw which also allows you to make straight cuts. The second reason to keep your chain tight is for your safety. A tight chainsaw chain is also important to sharpen the cutting teeth. Be sure to check out our post on How to Sharpen your Chainsaw.
A loose chain is the main reason why a chain jumps off the guide bar. If the chain comes off the guide bar it will damage your chain beyond repair. Below is a photo of a damaged chainsaw chain which jumped off the guide bar. You can notice a large gouge in the drive link in the center.
Damaged drive links can wreck havoc on your chainsaw. The damaged drive links can become severely deformed and if placed back on your chainsaw can wear out your guide bar much quicker. Remember that guide bars are precisely machined to fit a specific width of drive link, a damaged drive link can wear out new grooves in the guide bar and render it unusable. If your chain ever comes off the guide bar, you should closely inspect your chain for damaged drive links and discard it if you do find any damage.
Why won’t my chain tighten on my chainsaw?
To tighten a chainsaw you use the tightening screw, however, there are two other nuts which hold the plastic cover and the bar in place. If these nuts are tightened too much before using the tightening screw, then the bar will not move forward because there is too much friction holding it tight. Be sure to loosen those nuts so the guide bar can freely move forward when you turn the tightening screw and then retighten them after your chain is sufficiently tight.
The photos below show the nuts which need to be loosened to allow the guide bar to stretch the chain out.
Angel is a Cuban immigrant who grew up with backyard chickens and a yard-loving abuela. He is our “gear guy” who can never have too many pairs of gloves or weed whacker attachments.