Chainsaw sharpening stones come in three diameters: 5/32 inch, 3/16 inch, and 7/32 inch. The right size depends on your chain’s pitch, not your sharpener’s brand. Get it right and a rotary tool or a 12V sharpener can keep a chain cutting well for years.
Most homeowners meet these stones through a Dremel style attachment kit or a small bench grinder. The stones are almost always aluminum oxide, which cuts steel fast but wears with heavy use. Diamond coated bits last far longer, though they cost more and suit harder edges.
This guide covers sizes, materials, and fit, so you buy the right stone the first time.
How to Choose the Right Chainsaw Sharpening Stones for Your Chain
Chain pitch decides the diameter, not the saw or sharpener brand.
- 5/32 inch fits 3/8 inch low profile or 1/4 inch pitch chain
- 3/16 inch fits .325 inch pitch chain
- 7/32 inch fits full 3/8 inch or .404 inch pitch chain
That mapping comes straight from Oregon’s own sizing chart. Every brand of chainsaw sharpening stones follows the same logic, even when the packaging stays quiet about it.
Check the pitch stamped on your bar or a drive link before you buy. Guessing is the fastest way to end up with the wrong stone.
Our tool we use to double check chain fit confirms pitch and gauge in under a minute.
Prefer more control and less heat risk. See our traditional file sharpening compared to stones page before you buy a powered setup.
Aluminum Oxide vs Diamond: Which Stone Lasts Longer
Most homeowner chainsaw sharpening stones are aluminum oxide. It cuts steel fast and stays cheap, but it wears down with heavy grinding.
Diamond coated bits last far longer and run cooler, since they need fewer passes. They cost more, and it pays off on carbide tipped chain, where aluminum oxide wears fast. For a typical steel chain on a homeowner saw, aluminum oxide is still the practical default.
See our using a rotary tool to sharpen the chain page for stone speed and safe angles.
For the wider picture, our chainsaw sharpener comparison guide covers more ground than stones alone.
| Kit | Type | Best for | Price band | |
|---|---|---|---|---|
| Dremel A679-02 | Rotary tool attachment, aluminum oxide stones | Powered touch ups with a rotary tool you already own | Around $25 | |
| Oregon Universal Field Kit | Manual files, 5/32, 3/16, 7/32 inch | Hand sharpening without a power tool | Under $15 | Price |
Dremel A679-02 Sharpening Kit
Dremel A679-02 Sharpening Kit
Best Overall
Rotary tool attachment | 4 aluminum oxide stones | around $25
This kit bundles three sharpener attachments, chainsaw, lawn mower, and garden tool, plus four stones. The manufacturer lists it as compatible with common rotary tool models, including the 4300, 4000, 3000, 200, and 100. It suits anyone who already owns a Dremel and wants chain touch ups without buying a dedicated sharpener.
The manufacturer does not publish the exact diameter or grit of each stone in the box. Measure a stone against your chain before you assume it matches your pitch. Skip this kit if you want a tool built just for chainsaws, not mower blades and garden tools too.
Pros
- One kit covers chainsaw, mower blade, and garden tool sharpening
- Works with a long list of common rotary tool models
- Stones are small enough for quick touch ups between full sharpenings
Cons
- Stone diameters are not labeled on the manufacturer page
- Aluminum oxide wears faster than diamond under heavy use
- Needs a rotary tool that is not included in the box
Oregon Universal Field Sharpening Kit
Oregon Universal Field Sharpening Kit
Best Value
Manual files | 5/32, 3/16, and 7/32 inch round files plus a flat file | under $15
Oregon builds this kit around its own sizing chart, so the three files match every common chain pitch. A filing guide holds the correct angle while you work, which helps if you are new to hand filing. It is the pick for anyone who wants an exact match to Oregon’s own pitch chart in one box.
Hand filing takes longer than a rotary tool stone, and these files wear out with use just like stones do. Skip this kit if speed matters more than precision, or if you already own a powered sharpener and just need replacement stones. Some sellers also bundle a generic chainsaw sharpening stone set across all three sizes, which works as a cheap backup as long as you confirm each stone’s stamped size before you use it.
Pros
- Covers all three standard pitch sizes in one kit
- Filing guide keeps the angle consistent
- No power tool or battery required
Cons
- Slower than a rotary tool or powered sharpener
- Files dull with use and need replacing
- No case marking to stop you grabbing the wrong diameter
Common Chainsaw Sharpening Stone Mistakes
The single biggest mistake with chainsaw sharpening stones is guessing the diameter instead of checking the pitch stamp. A stone that is too small rounds over the cutting edge. A stone that is too large can gouge the tooth or hit the depth gauge.
Skipping the depth gauge is another common miss. A sharp cutter with a tall rocker still cuts slowly and grabs unevenly. Check the gauge every two or three sharpenings, powered stone or hand file, so the chain keeps cutting the way it should.
For the full picture beyond stones, our full toolkit for keeping a chain sharp rounds up files, gauges, and vises in one place. For setup on a powered bench unit instead of a rotary tool, see our guide on step by step electric sharpener instructions.
The bottom line: match the stone diameter to your chain pitch first, then choose powered stones for speed or a manual file kit for control. The Dremel A679-02 kit is the simplest way into powered stone sharpening if you already own a compatible rotary tool.
For everything else in this category, browse our more chainsaw sharpening gear breakdowns archive.
Frequently Asked Questions
What size chainsaw sharpening stones do I need for my saw?
It depends on chain pitch, not saw brand. Match your bar’s pitch stamp to the 5/32, 3/16, or 7/32 inch chart above before you buy.
Are these stones the same as files?
No. Stones are abrasive bits that spin in a rotary tool or a powered sharpener. Files are hand tools you push through the cutter, though both come in the same set of diameters.
How long does a chainsaw sharpening stone last?
It depends on the material and how often you sharpen. Aluminum oxide stones wear down with regular use, while diamond coated bits hold their shape far longer under the same workload.
Can I use a diamond stone on any chain?
Yes, diamond bits work on standard steel chain and carbide tipped chain alike. They cost more, so most owners save them for carbide chains where aluminum oxide wears out fast.
How do I know when a stone is worn out?
A worn stone rounds the cutting edge instead of leaving a clean, angled facet. If sharpening takes noticeably longer than it used to at the same speed, the stone has lost its bite.
Sources
- Dremel: A679-02 Sharpening Kit product page. https://www.dremel.com/us/en/p/a679-02-26150679ad
- Oregon Products: Saw Chain Sharpening Tools, diameter to pitch reference. https://www.oregonproducts.com/en/saw-chain-sharpening-tools/c/02_01
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