How Tight Should a Chainsaw Chain Be?

If you want to cut firewood or start a woodworking project, you need to ensure your chainsaw is working correctly. Something as simple as a chainsaw’s chain tightness can seriously impact its functionality and safety. So, how tight should a chainsaw chain be? In this guide, we will show you everything you need to know about tightening your chainsaw chain, including why you need the correct tension, how often you should tighten it, and much more!

In general, a chainsaw chain should be loose enough for your hands to move it on the bar. However, it should also be tight enough to prevent the drive links from disengaging from the guide bar when pulled.

Dangers of a Loose and Tight Chainsaw Chain

chainsaw cutting wood

A chainsaw chain that is too tight or loose will give you many problems while working. If your chainsaw chain is too loose, it will not feed into the wood properly. You will have to use your weight against the guide bar to force the chainsaw into the wood, causing the guide bar to bend. Pay attention to how the chainsaw cuts, as any cuts made this way will usually be slanted.

Additionally, with a loose chain running faster than 60 feet per second, your chain will probably derail. A derailed chain can cause serious physical injury if you are not careful.

If your chainsaw chain is too tight, the bar nose and drive sprocket will become too stressed, resulting in premature wear. Furthermore, the chain can snap instantly and eat its way into the bar rails. As a result, the chainsaw will consume more bar oil, and both the clutch and bearing could get damaged.

How to Tighten a Chainsaw Chain

closeup of chainsaw chain cutting wood

Before tightening your chainsaw chain, you must allow it to cool down if you have been using it to cut wood. A used chain gets hot and expands, so tightening it when hot will cause it to hug the bar too tightly. As a result, you will burn your clutch, guide bar, and a lot of bar oil.

So, give your chainsaw chain at least 3 minutes to cool down. Meanwhile, you can find a working surface, such as a table, bench, or tree stump. Regardless of the type of chain you use, whether a full chisel, semi-chisel, or low profile, you can follow these steps to tighten a chainsaw chain properly.

Step 1: Locate the Tension Adjustment Screw

With the chainsaw cooled down, place it on a working surface and look for the chain tension adjustment screw. It will usually be between the guide bar and the inside bucking teeth or the two bar nuts on the side cover. Once you find the chain tension adjustment screw, ensure that its head is visible by wiping off any dirt using a rag or brush.

Step 2: Loosen the Bar Nuts

Loosen the two bar nuts on the clutch cover so that you can easily adjust the chain tension pin. Otherwise, you will destroy the bar or the threads on the tensioning pin. Once the nuts are loose, you will be able to move the bar up and down through its nose. Disable the chain brake and turn off the engine before proceeding to the next step.

Step 3: Hold the Bar Correctly

Before you manipulate the adjustment screw, you must hold the bar by its nose. This allows the chain to maintain tension when you are cutting wood. If your guide bar is longer than 28 inches, following this step is even more critical since longer guide bars have more play in them.

Step 4: Adjust the Tension

Take the screwdriver end of your scrench and turn the adjustment screw to either increase or decrease the chain tension. If you turn it clockwise, the chain tension will increase, whereas chain tension will decrease if you turn it anticlockwise. It is convenient to make quarter or half-turns on the screw. However, if your chainsaw is new, you will probably need to make full turns to get the proper chain tension.

Then, make sure that the chain is snug with the bar. No light should pass through the bar rails and the chain.

Step 5: Test the Tension

With the chain perfectly snug, it is time to test it with your fingers. Use your index finger and thumb to give the bottom of the chain loop a light tug. Do the same with the middle section. Both sections should snap back without any problem. Avoid tugging around the clutch cover or nose as the chain would be too tight in those spots.

Another way to test the tension of a chainsaw chain is by applying the three-quarters rule. You should check if over 3/4th of the drive link is exposed. If over 3/4th of the drive link is exposed, the chain may derail at any moment.

Apart from that, you can also move the chain around the guide bar to see if it has the right amount of tension. It should feel smooth and move easily.

Step 6: Tighten the Bar Nuts

Finally, with the tension in the chain adjusted, you should tighten the bar nuts. While holding the nose of the bar, use the wrench side of your scrench to tighten the guide bar nuts on the clutch cover.

How Often Should You Adjust a Chainsaw Chain?

stihl chainsaw

Every new chainsaw has a break-in period. As a result, you need to adjust the chain more frequently than if you had a used chainsaw.

The break-in period allows any irregularities on friction surfaces to smooth out, so the rivets on the chain links are seated properly. It usually lasts between 5 to 15 tank fillings. After every few cuts, you should also check the chain tension and make any adjustments as necessary.

Additionally, make sure that you slightly loosen the chain after cutting wood during everyday use. This prevents the chain from gripping the bar too firmly after it cools down. It also ensures that the next time you run your chainsaw, it will be much easier on the bearings and clutch in the drive sprocket, preserving the lifespan of the chainsaw.

Frequently Asked Questions

man in blue overalls holding orange chainsaw

Can You Over Tighten a Chainsaw Chain?

It is possible to over-tighten a chainsaw chain, which can damage the chainsaw and cause serious injury. In general, a chainsaw chain should be loose enough for your hands to move it on the bar.

Why Does the Chain Keep Coming Off Your Chainsaw?

Chainsaw chains usually come off the bar because it is too loose. To keep the chain firm on your chainsaw, try these steps:

  • Take off the clutch cover and check if the guide bar is correctly seated on the adjustment pin.
  • Check if the threads on the bar studs have worn out. If they have, you should replace them.
  • Check the chain tension pin. It should move away from the powerhead when you turn the screw clockwise and towards the powerhead when you turn the screw anticlockwise. If this does not happen, you need a new pin.

Why Does My Chainsaw Chain Tighten On Its Own?

A chainsaw chain tightens on its own because of a dry chain and bar. To fix your chainsaw chain from tightening on its own, try these steps:

  • Check the oiler holes and make sure they are clean.
  • Check the bar oil tank and make sure that it is clean. If it is clean, something could be wrong with the oiler pump.
  • Make sure that you change the drive sprocket for every two chain replacements.


oregon chainsaw

While you may be eager to use your new chainsaw, you need to ensure your chainsaw chain is not too loose or tight. Otherwise, you may damage your chainsaw or hurt yourself. Simply put, your chainsaw chain should be somewhat loose on the guide bar but tight enough to prevent the drive links from coming off when pulled. Thanks to this guide, you can now use your chainsaw safely to cut trees and even to cut concrete!

Liam Weissman

Hello and welcome to PowerToolGenius! My name is Liam and for the last 9 years, I have worked extensively with various power tools and accessories. I have tested hundreds of different brands and models and understand the industry extensively and have been working with tools my entire life!

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