How to fit a Stihl chainsaw chain
Updated: 15 October 2026
You already have a loop that matches the bar, so this page shows how to fit a Stihl chainsaw chain without the saw starting under your hands. A battery left in a cordless saw can still drive the chain if the switch is bumped. Stop the saw, point the cutters forward, leave a small gap, and put oil in the tank before you cut. A compatible loop follows the same rules as a genuine one. If you are still matching pitch, gauge, and drive links, start with the [Stihl chainsaw chain comparison](/hub/forestry-tools/stihl-chainsaw-chain). A qualifying purchase through a link there can earn us a commission at no extra cost to you.
You already have a loop that matches the bar, so this page shows how to fit a Stihl chainsaw chain without the saw starting under your hands.
You already have a loop that matches the bar, so this page shows how to fit a Stihl chainsaw chain without the saw starting under your hands. A battery left in a cordless saw can still drive the chain if the switch is bumped. Stop the saw, point the cutters forward, leave a small gap, and put oil in the tank before you cut. A compatible loop follows the same rules as a genuine one. If you are still matching pitch, gauge, and drive links, start with the Stihl chainsaw chain comparison. A qualifying purchase through a link there can earn us a commission at no extra cost to you.
Our top picks
| Badge | Product | Bar length | Gauge | Drive links | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  Stihl Stihl PMMC3, 35 cm, 50 links | 35 cm | 1.1 mm | 50 | 8.8 | about £16.98 | View offer |
| Alternative |  Rotatech Rotatech 12 inch, 44 links, 2-pack | 12 inch | 1.1 mm | 44 | 7.3 | about £17.99 | View offer |
| Preis-Tipp |  CHAMSUREUK CHAMSUREUK 12 inch, 44 links, 3-pack | 12 inch | 1.1 mm | 44 | 8.5 | about £15.99 | View offer |
On this page
Stop the saw before you touch the chain
Take the power away before your gloves go near the cutters. On a petrol saw the engine must be off and not hot. On a cordless saw, remove the battery. On a mains saw, pull the plug. STIHL's UK guides say you never tension a chain with the engine running, and a new loop will still cut skin when the motor cannot turn.
Petrol refuelling is separate from fitting. STIHL says you refuel at least 3 metres from where you will start, with the engine off and not hot. If the saw is used for paid work, the Health and Safety Executive expects training and proper protective clothing, which gardening gloves do not replace.
Point the arrows forward and seat the sprocket
The arrows on the cutters point in the direction of rotation, and the drive links sit in the sprocket. On a conventional bar the chain runs out along the top and returns underneath, so the arrows on top should point towards the nose. STIHL's replacing guide gives that order, then the bar nuts once the gap is set. A compatible chain uses the same marks, so follow the arrows rather than the logo on the bar. Work the links into the groove as far as the nose before you draw the nuts up. If a link stays proud, leave the tensioner alone.
How tight is tight enough
While you set the chain, leave about 1 to 2 mm between it and the middle of the bar, then tighten the bar nuts. That gap is the figure in STIHL's replacing guide. The chain should then sit snug along the underside, with the brake released and the engine stopped. A chain that is too tight strains the saw, and one that hangs in a loose loop under the bar is too slack.
If you set the tension on a hot bar, slacken it when the saw has cooled, because the chain tightens as the metal contracts.
Put chain oil in every kind of saw
Petrol, cordless, and electric saws all need chain oil before you cut. STIHL's replacing guide says so for each power type. Without oil the cutters overheat, and dry running damages the rail.
The easy miss is a charged cordless saw, a new chain, and the oil cap shut. Chain oil does not go in the fuel tank, and filling it on a battery saw is not that 3-metre petrol refuel. A genuine loop and a compatible one take the same oil, and the genuine Stihl chain versus a compatible loop page is about edge life, not a different filling routine.
When not to carry on
A loop that sits proud, or will not seat with the tension fully slack, is too thick, too short, or the wrong gauge, and another turn of the adjuster will not change those sizes. Match the bar in the Stihl chainsaw chain buying guide instead of forcing the nuts. Do not fit a chain if a tooth is already damaged or chipped, the wear marker has gone, or it has already run dry, because a careful gap will not hide that damage.
If you still need to choose a loop, use the best Stihl chainsaw chain page.
Common questions
Which way do the arrows on a Stihl chain point?
The arrows point the way the chain rotates. On the top of a conventional bar they should aim towards the nose. If they point the other way, take the loop off and turn it. Tightening will not correct a backwards loop, and a compatible chain uses the same marks.
How tight should a chainsaw chain be?
Leave about 1 to 2 mm between the chain and the middle of the bar, then tighten the bar nuts. It should sit snug, with the brake released and the engine stopped. If it will not move, it is too tight and will strain the saw. A loose loop under the bar is too slack.
Do cordless and electric saws need chain oil?
Yes. STIHL's UK replacing guide calls for chain oil on petrol, cordless, and electric saws. The battery or the mains lead does not lubricate the bar. Refuelling at least 3 metres from the start point, with the engine off and not hot, applies to petrol, not to oil on a battery saw.
Should I tension the chain while it is hot?
You can set the tension after a cut, then slacken the chain once the bar has cooled. If you tightened the chain while it was hot, STIHL's tightening guide says you slacken it when cool, because a hot setting becomes tighter as the metal contracts. Never adjust the tension with the engine running.
What if the chain will not go into the bar?
Stop. The chain is too thick, too short, or too tight to enter the groove. Slackening the adjuster fully is the only extra try. If the drive links still sit proud, match pitch, gauge, and drive-link count in the buying guide instead of forcing the nuts.
Do I release the chain brake to check tension?
Yes, but only with the engine stopped, the battery removed or the plug out, and with gloves on. On a QuickStop Super, STIHL says you also press the brake lever on the lower handle to release the brake, and only for that brake. Never check with the engine running.
Does a new chain remove kickback?
No. A new loop, including one sold with a low-kickback description, does not remove kickback or replace training. If the saw is used at work, or the cut is off the ground, the Health and Safety Executive expects a trained operator and proper protective clothing.
Related pages
Sources
Public UK and product-listing sources, last accessed 15 October 2026.
- HSE — Working with chainsaws (retrieved 15.10.2026)
- HSE — INDG317 Chainsaws at work (retrieved 15.10.2026)
- HSE — Chainsaw personal protective equipment (retrieved 15.10.2026)
- PUWER 1998 — Regulation 5 (retrieved 15.10.2026)
- Consumer Rights Act 2015 — Section 9 (retrieved 15.10.2026)
- STIHL GB — Chains and bars (retrieved 15.10.2026)
- STIHL GB — Replacing a chainsaw chain (retrieved 15.10.2026)
- Amazon.co.uk — Example Stihl PMMC3 listing (retrieved 15.10.2026)