How to tighten your chainsaw chain
Want to get the tension right on your chainsaw? We explain quick chain tensioners, side chain tensioners and front chain tensioners.
11.11.2024
Overview: how to tighten a chainsaw chain
- Shut off your chainsaw engine. Remove the battery if it’s a battery chainsaw; disconnect the power supply if it’s an electric chainsaw
- Place the chainsaw on a firm, level surface
- Release the chain brake
- Always follow the instructions
- Don’t forget to wear safety gloves so that you don’t injure yourself on the sharp teeth of the chain
Yes, a chainsaw chain should be snug but not overly tight. A correctly tensioned chain should be snug against the underside of the bar but still able to move easily when the chain brake is released.
A chainsaw should always be tensioned so that the saw chain is in contact with the underside of the guide bar. With the chain brake disengaged, you should be able to move the chain smoothly around the bar by hand.
If you re-tension the chain at operating temperature, reduce the tension as soon as the chain has cooled down. This will ensure that the guide bar and crankshaft bearings are not overloaded.
An electric chainsaw is tightened in the same way as any other chainsaw. Just make sure it's unplugged first. The exact method depends on the tensioning mechanism and varies for chainsaws with quick chain tensioners, side chain tensioners or front chain tensioners.
Saw chains are subjected to high loads during operation. Every time a cutting tooth makes contact with the wood, a sudden peak load is applied to the chain. Abrasion, dirt, sawdust and wood dust also cause mechanical wear on the sprocket, bar and chain. It is normal for the chain to be tightened regularly to compensate for this wear.
The chain tension should be adjusted when the saw chain no longer makes contact with the underside of the guide bar.
How tight should a chainsaw chain be? – How to tell when you need to tighten your chainsaw chain
You need to tighten your saw chain every so often because it is the part that encounters the most strain when you use your chainsaw: every time a tooth goes into wood, the chain experiences an abrupt peak of stress in terms of impact and friction. The accumulated abrasion, dirt, and sawdust generated also cause additional mechanical wear on the sprocket, chain and other parts. So it’s no surprise that the chainsaw tension will need adjustment over time.
If you can see that the saw chain no longer fits to the bottom of the guide bar, you need to tighten it – a correctly tensioned saw chain is snug to the underside of the bar but can still be easily moved round by hand when the chain brake is released. If you have a STIHL chainsaw with QuickStop Super, you also need to press the brake lever on the lower handle to release the chain brake. Be aware that the saw chain heats up during normal operation and therefore expands; you should also tighten the saw chain if it has more play after heating up.
If you tighten the saw chain at operating temperature, remember to loosen it – reduce the tension – again once it has cooled down. If the chainsaw chain tension is too high, it puts extra strain on parts of the chainsaw, which could cause damage.
We recommend you check the chainsaw chain tension every time before using your chainsaw.
Note: remember to consider your own safety when you check or tighten your chain
- Never check or tighten the chain when the chainsaw engine is running.
- Wear suitable protective gloves.
- You can burn yourself on hot parts of the chainsaw engine or muffler if you try to check or tighten the chain at operating temperature.
- For a battery or electric chainsaw, take the necessary measures to ensure that it cannot turn on (remove the battery, disconnect the plug).
- Check the saw chain for wear or mechanical damage (cracking, chipping, distortion) and do not use your chainsaw if the chain is damaged.
HOW TO Tighten a chainsaw chain with the STIHL quick chain tensioner: step-by-step instructions
If you have a STIHL chainsaw with a quick chain tensioner, it is quick, easy and convenient to tighten the saw chain. You can identify which STIHL chainsaws feature a quick chain tensioner because there is a B in the model name; MS 181 C-BE, for example. Here’s how it works:
Shut off the engine. If you have a battery chainsaw remove the battery, and for an electric one disconnect the mains plug.
Release the chain brake by pulling the chain brake handle towards you.
Pull out the handle on the wingnut for the quick chain tensioner, then loosen it without removing it – just one turn is usually enough.
Lift the chainsaw guide bar by the tip, particularly if it is long. Hold it up.
Tighten the chain by turning the adjustment wheel clockwise as far as it will go.
Retighten the wingnut by hand and fold the handle back in.
After you have folded the wingnut handle back in, you can bring the chainsaw guide bar back down again.
To check the chainsaw chain tension, pull the chain to see if it moves around easily – you must wear protective gloves to do this. The chain should move around the guide bar without a problem but also fit snugly to the bottom of it. Try lifting the top part of the chain at the middle of the guide bar too; it shouldn’t lift more than around 5 mm.
Rather than using your hands to pull the chain around, you can instead use the shaft of the KombiTool supplied; this reduces the risk of injury as you do not come into direct contact with the teeth of the chain.
Video instructions: How to tighten your chainsaw chain
How to tighten a chainsaw chain with a side chain tensioner – step-by-step instructions
The side chain tensioner is a tried-and-tested component of most STIHL chainsaws. It provides convenient access to the chain tensioner part and reduces the risk of contact with hot parts of the chainsaw engine.
If you have a model with QuickStop Super, remember to press the QuickStop lever on the rear handle when you try to move the chain around.
Shut off the engine. If you have a battery chainsaw remove the battery, and for an electric one disconnect the mains plug.
Release the chain brake by pulling the chain brake handle towards you.
Use the KombiTool to loosen the fixing nut or nuts on the chain sprocket cover, but don’t unscrew the nut completely; it’s usually enough to loosen it by one or two turns.
Lift the chainsaw guide bar by the tip, particularly if it is long. Hold it up.
Turn the tensioning screw clockwise with the KombiTool screwdriver until the tension is correct.
Pull or push the chain round the guide bar by hand to distribute the chain tension evenly. You may need to slightly tighten or loosen the tension after doing this.
Tighten the fixing nut or nuts with the KombiTool.
After you have tightened the fixing nut, you can bring the chainsaw guide bar back down again.
To check the chainsaw chain tension, pull the chain to see if it moves around easily – you must wear protective gloves to do this. The chain should move around the guide bar without a problem but also fit snugly to the bottom of it. Try lifting the top part of the chain at the middle of the guide bar too; it shouldn’t lift more than around 5 mm.
Rather than using your hands to pull the chain around, you can instead use the shaft of the KombiTool supplied; this reduces the risk of injury as you do not come into direct contact with the teeth of the chain.
How to Tighten a chainsaw chain with a front chain tensioner – step-by-step instructions
Only a few STIHL chainsaws have a front chain tensioner. They work in the same way as the side chain tensioner and are located in a different position.
Shut off the engine. If you have a battery chainsaw remove the battery, and for an electric one disconnect the mains plug.
Release the chain brake by pulling the chain brake handle towards you.
Use the KombiTool to loosen the fixing nut or nuts on the chain sprocket cover, but don’t unscrew the nut completely; it’s usually enough to loosen it by one or two turns.
Lift the chainsaw guide bar by the tip, particularly if it is long. Hold it up.
Turn the tensioning screw clockwise with the KombiTool screwdriver until the tension is correct.
Pull or push the chain round the guide bar by hand to distribute the chain tension evenly. You may need to slightly tighten or loosen the tension after doing this.
Tighten the fixing nut or nuts with the KombiTool.
After you have tightened the fixing nut, you can bring the guide bar back down again.
To check the chainsaw chain tension, pull the chain to see if it moves around easily – you must wear protective gloves to do this. The chain should move around the guide bar without a problem but also fit snugly to the bottom of it. Try lifting the top part of the chain at the middle of the guide bar too; it shouldn’t lift more than around 5 mm. Rather than using your hands to pull the chain around, you can instead use the shaft of the KombiTool supplied; this reduces the risk of injury as you do not come into direct contact with the teeth of the chain.
How to tighten your chainsaw chain: Operating instructions for STIHL chainsaws
Download the operating instructions for your STIHL chainsaw here at your convenience.
