To sharpen a chainsaw correctly, identify the chain first and use its specified file, angles and depth-gauge setting. The saw model or bar length alone does not tell you which sharpening kit to buy. A replacement chain may differ from the one originally supplied.
This guide covers ordinary round-file maintenance. Square-ground, carbide-tipped and specialized chains can require different equipment or professional service.
Identify the chain before removing metal
Find the chain series or identification marking and the manufacturer’s maintenance chart. Write down the file diameter, filing angles, depth-gauge specification and wear limits. If you cannot establish those details, ask a servicing dealer to identify the chain rather than guessing.
Sharpen serviceable cutters; replace a chain with structural damage or wear beyond its permitted limits.
Decide whether sharpening is the right repair
Reduced cutting performance, a tendency to wander, chatter or unusual cutting debris can justify an inspection. Stop after contact with soil, stone or metal. Do not continue forcing the saw through wood while deciding whether it needs attention.
Check the bar, lubrication and tension as well as the cutters. A crooked cut does not prove the chain is simply dull. Cracks, broken components, severe damage or a chain that cannot maintain proper tension need appropriate service or replacement. Sharpening cannot repair a damaged rivet or stretched-out chain.
Gather a matched filing setup
Use a proper saw-chain round file of the specified diameter, a suitable handle and a compatible guide. An arbitrary tapered file does not maintain the required cutter shape. You may also need a flat file and the correct depth-gauge tool, plus a marker and a secure vise.
A combined filing guide can maintain cutters and depth gauges together, but only when it is the correct version for the chain. Keep its instructions with the kit. Mark the pouch with the chain series and file size so similar-looking files do not become interchangeable in your toolbox.
Isolate, clean and secure the saw
Stop the engine and let the saw cool. Unplug a corded saw or remove its battery; follow the gasoline model’s procedure to prevent accidental starting. Wear gloves and eye protection for maintenance. Clean enough debris away to inspect the chain clearly.
Secure the bar using a suitable vise without clamping the chain or distorting the bar. Set chain tension for filing as instructed. Use the chain brake while working on cutters; release it only as needed to advance the isolated chain by hand, then reset it. A brake is not a substitute for disconnecting the power source.
Choose a reference cutter and file consistently
Inspect the cutters and select the reference tooth according to the chain maker’s instructions, usually considering the shortest or most worn serviceable cutter. Mark where you start so you can recognize a complete circuit. Maintain the specified file position and angles with the guide.
For ordinary round filing, work from the cutter’s inside toward its cutting edge using controlled forward strokes, lifting the file on the return. Complete one cutter orientation, then reposition to work the other side as the guide directs. Compare cutter lengths and edges rather than assuming an identical stroke count automatically makes unequal teeth equal.
Check depth gauges with the proper tool
The depth gauge ahead of a cutter controls how much wood that cutter takes. Its relationship to the cutting edge changes as the tooth is sharpened. Check it with the tool and specification for the exact chain.
Where adjustment is required, use the prescribed flat-file procedure. Do not remove extra material to make the saw feel more aggressive. A depth gauge set too low increases kickback risk. Preserve the required shape and do not file safety features or drive-link humps unless the manufacturer explicitly includes them in its procedure.
Inspect the finished loop before cutting
Confirm you completed both sets of cutters, checked the depth gauges and removed loose filings. Inspect for damage you may have uncovered while cleaning. Restore the operating tension and reassemble any parts removed using the saw manual.
Check lubrication and normal safety functions before testing on suitable, securely supported wood with the required operating protection. If the saw still pulls sideways, chatters or needs unusual force, stop and investigate the bar, sharpening geometry and other possible causes. Repeating the same filing strokes without diagnosing the problem can waste the chain.
Know when a dealer or grinder is the better choice
A dealer can assess damage and restore geometry when hand filing would require excessive correction or you cannot identify the chain. Ask whether the remaining cutter length and other components justify the work. Keep a correctly matched spare chain if downtime would interrupt a project.
A powered grinder still needs the correct wheel, angles, depth stops and operating technique. It is not automatically more accurate than a guided file. Follow its instructions and do not grind a cutter until it overheats. For occasional maintenance, a matched hand-filing kit may be simpler to store and use.
Questions readers ask
What angle should I use?
Use the chain maker’s specification. Common angles are not universal; specialized ripping or other chains can differ. Keep the correct chart with your filing kit.
How many strokes does each cutter need?
Enough to restore the specified shape and a sound edge while preserving service limits. Counting strokes helps consistency, but inspect and compare cutters because damage may be uneven.
Can I lower the depth gauges every time by eye?
No. Check with the correct tool and adjust only as instructed. Guessing at the clearance can change cutting behavior and increase kickback risk.
Make identification part of every sharpening session
A labeled chain, matched file and guide, and a deliberate inspection are more useful than a universal angle or stroke count. Keep the maintenance chart with the saw, correct problems early, and replace damaged components instead of trying to file them back into service.
Sources and editorial approach
This guide was refreshed in October 2026 using primary sources and original practical analysis. It does not claim hands-on equipment tests. The exact tool and accessory instructions govern their operation.
STIHL: sharpening cutters and depth gauges
STIHL: using a compatible filing guide