Tensioning the Saw Chain Properly

Why is proper chain tension so important?

While sawing, the saw chain moves at high speed along the guide bar. To ensure it is guided safely, the tension must be correct.

A saw chain that is too loose may run erratically or, in the worst case, come off the guide bar. If, on the other hand, it is too tight, it creates unnecessarily high friction and stress. This can cause the chain and guide bar to heat up more and wear out faster.

The correct setting lies somewhere in between: The chain must fit snugly against the guide bar while still being able to move according to the manufacturer’s specifications.

When should the saw chain be tensioned?

Chain tension should not only be checked when installing a new chain. Heat generated during sawing can cause the chain’s length or tension to change.

You should check it especially frequently:

For extended sawing jobs, it is recommended to check the tension regularly.

The exact procedure varies depending on the chainsaw model. Therefore, the manufacturer’s instruction manual always takes precedence. For many traditional tensioning systems, the adjustment generally works as follows:

1. Securely park the chainsaw

Turn off the chainsaw completely and secure it against accidental startup. For a gas-powered chainsaw, the engine must be off. For battery-powered tools, follow the manufacturer’s instructions - for example, remove the battery. Unplug electric chainsaws from the power source.

The chain should also be cool before retensioning.

2. Put on protective gloves

The cutting teeth of a saw chain are very sharp, even when the chainsaw is turned off. Therefore, wear suitable protective gloves (Item No. 45881) when checking and tensioning the chain.

3. Loosen the guide bar mounting

With conventional tensioning systems, the nuts or fasteners on the sprocket cover are loosened slightly.

They are not removed completely. The guide bar simply needs to be loose enough to allow the chain tension to be adjusted.

For chainsaws with tool-free chain tensioning, the procedure is different. Follow the manufacturer’s instructions in this case.

4. Lift the tip of the guide bar

On many chainsaws, the tip of the guide bar should be lifted slightly during tensioning. This prevents the setting from changing later due to movement of the bar.

5. Adjust the chain tension

Now tension the saw chain using the tensioning device according to the manufacturer’s instructions.

Make sure the drive links are seated correctly in the groove of the guide bar and that the chain runs smoothly all the way around.

The chain should not sag noticeably on the underside of the guide bar.

6. Check the chain tension

Next, check the tension according to your chainsaw’s owner’s manual.

On many models, the chain should fit snugly against the bar and still be movable with gloved hands. The drive links must not pop out of the guide groove.

The correct amount of slack can vary depending on the chainsaw, bar, and chain. Therefore, you should not rely solely on a general rule of thumb.

7. Reattach the guide bar

Continue to hold the tip of the guide bar in the correct position and tighten the fasteners according to the manufacturer’s instructions.

Afterward, check the chain tension again. If it has changed while tightening, the process must be repeated.

Caution When the Saw Chain Is Hot

The guide bar and saw chain heat up during operation. This can cause the chain tension to change.

Therefore, a hot chain should not simply be retensioned to be particularly tight. As it cools down, it may contract and become too tight.

Check the chain during operation according to the manufacturer’s instructions and check it again after it has cooled down.

How can I tell if a saw chain is too loose?

Signs that a chain is too loose include noticeable sagging on the underside of the guide bar or the drive links no longer being guided securely in the bar groove.

In this case, you should stop working and check the chain tension.

Unusual noises or changes in how the saw runs are also reasons to shut off the chainsaw and inspect the chain, guide bar, and drive mechanism.

What happens if the chain is too tight?

Excessive tension is also problematic. It increases friction between the saw chain and the guide bar and puts strain on the components involved.

Possible consequences include:

Therefore, do not tension the chain as tightly as possible; instead, follow the manufacturer’s specifications correctly.

Also check the chain lubrication

A correctly tensioned chain alone is not sufficient for reliable operation. The chain lubrication must also be working properly.

Therefore, regularly check the chain lubricant level and the lubrication system’s operation according to the owner’s manual.

An inadequately lubricated chain creates additional friction and can cause significant wear on both the chain and the guide bar.

Check the Saw Chain and Guide Bar for Wear

If you have to retension the chain unusually often or if it can no longer be adjusted properly, the entire cutting system should be inspected.

Check the following in particular:

Damaged or excessively worn components should not be used any further.