Chainsaw File Size Finder
Why this tool? Chainsaw teeth are curved hooks. To sharpen them, your round file must fit perfectly inside that curve. A file that is too big or too small will ruin the cutting edge.
How to use: Check the "Pitch" stamped on your guide bar (e.g., 3/8 LP, .325). Click the matching button below to find your exact file size and grinding angles.
The Ultimate Guide to Chainsaw Sharpening
Many people think a chainsaw cuts like a knife. It doesn't. It cuts like a wood chisel. The "Cutter" tooth scoops out a chip of wood. The round file you use creates the "Hook" (the C-shape) of that chisel.
- File too big? It sits high on the tooth and files away the cutting edge. You get a sharp-looking tooth that won't cut.
- File too small? It sinks deep into the hook, creating a thin, razor-like edge that breaks or dulls instantly.
Tips & Tricks for a Razor Edge
1. The "Sharpie Trick"
The hardest part of sharpening is knowing where you started. Before you begin, take a black permanent marker and color the top of the first tooth you sharpen. When the black tooth comes back around, you know you are finished.
2. Tension is Key
Tighten your chain slightly more than usual before filing. This stops the teeth from wobbling while you push the file, giving you a cleaner, more consistent edge. Remember to loosen it back to normal tension before cutting!
3. Use a Stump Vise
You cannot sharpen accurately if the saw is moving. If you are in the woods, hammer a Stump Vise into a log and clamp your bar. It acts like a third hand and is essential for getting the angles right.
The "Dust Test": When to sharpen
If your saw is producing fine powder instead of wood chips, stop immediately. You are dull. Continuing to cut creates friction heat that will ruin your bar rails and stretch your chain. A sharp chain pulls itself into the wood; if you have to push down, it's time to file.
Depth Gauges (The "Rakers")
In front of every cutting tooth is a small metal bump called the Depth Gauge (or Raker). This controls how much wood the tooth bites. Think of it like taking a slice of cheese:
- Rakers too high: The knife glides over the cheese without cutting (Saw creates dust, won't cut).
- Rakers too low: The knife digs in too deep and gets stuck (Saw is "grabby," jerky, and vibrates heavily).
Every 3-4 times you sharpen the teeth, use a flat file and a depth gauge tool to lower the rakers to the recommended setting (usually .025").
Manual Filing vs. Electric Grinders
Manual Filing: Best for longevity. A file removes very little metal, so your chain lasts longer. It can be done anywhere in the woods. However, it requires practice to hold the correct angle.
Electric Grinders: Best for fixing damage. If you hit a rock, a file will take forever to fix the damage. An electric grinder (like the ones linked above) restores the edge in seconds. However, it removes more metal, shortening the life of the chain.
