How to Put a Chain on a Chainsaw & Safety Operations
Learn how to correctly install a new or sharpened chain on a chainsaw guide bar and follow essential safety practices before every use.
Tools Needed
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Instructions
Safety First — Always
Before doing anything, make absolutely sure the chainsaw is OFF and the spark plug wire is disconnected (gas) or battery is removed (electric/battery). Wear cut-resistant gloves — even a still chain can cut. Work on a stable surface like a workbench.
Remove the Side Cover & Bar
Use the bar wrench (usually included with the saw) to loosen and remove the nuts on the side cover. Pull off the cover. Slide the guide bar forward to release tension, then remove the old chain from around the bar and drive sprocket.
Clean the Bar and Sprocket
With the cover off, clean out any sawdust and debris from the bar groove, oil holes, and around the sprocket using a flat screwdriver or brush. Clogged oil holes cause the chain to run dry and wear out fast.
Identify Chain Direction
Chains only go on in one direction. Look at the cutting teeth — the sharp angled edge must face FORWARD on the top of the bar (away from the saw body). Hold the chain up to confirm direction before installing.
Loop Chain onto the Bar
Loop the new chain around the drive sprocket first, then work it into the groove along the bottom and tip of the bar, and back along the top. Make sure all drive links are seated in the bar groove all the way around.
Reinstall Bar and Adjust Tension
Slide the bar back onto the mounting posts while keeping chain in groove. Reattach the side cover loosely. Use the tensioning screw (usually a small screw on the side plate) to tighten the chain until it snaps back when pulled — it should be snug but still rotate freely by hand. Tighten the cover nuts fully.
Final Safety Check Before Starting
Check that the chain brake (front hand guard) moves freely. Confirm the chain catcher is in place. Check the oil reservoir is full (bar/chain oil). Start the saw, let it warm up at idle, then do one final tension check — chains stretch when warm. Never run a loose chain.
Ongoing Safety Operations
Always wear: cut-resistant chaps or pants, chainsaw gloves, helmet with face shield, hearing protection, and steel-toed boots. Never cut above shoulder height. Keep both hands on the saw. Be aware of kickback — it happens when the nose of the bar contacts something. Engage the chain brake anytime you are not actively cutting.
