How to Sharpen a Chainsaw With a Round File

Chainsaw Sharpening Time?

How do you know when it’s time to sharpen teeth on a chainsaw?

Common Answer: “When you see sawdust coming out of the chainsaw, you need to sharpen it.”

While that IS true, why wait until then? At that point, it’s been dull for a while, and under-performing. Some folks give two to four strokes to sharpen a chainsaw with a round file at every gas fill up, just to maintain really sharp edges, and high performance, straight cuts.

Before You Sharpen a Chainsaw With a Round File

I previously wrote in brief about the chainsaw sharpening process, but what I’m telling you here is much more detailed.

CAUTION: It is important to read the entire manual of a chainsaw before you use it (or sharpen it, for that matter). It is a very fast-moving power tool that can be dangerous when mishandled. Note, however, that the directions may need to be somewhat amended when it comes to sharpening.

ASIDE: Always store your file in the container it came in, (or in a straw), to maintain its cutting ability.

TIP: An important tip to make sure the teeth edges have the correct angles is to always use a file guide (even if you’re a professional with vast experience in chainsaw sharpening). If you don’t, you will eventually lose the angles on the teeth.
Nobody’s THAT steady!

SAFETY: Even if you are very experienced working with outdoor power tools, beware. I advise you to be extremely careful. Start by wearing a pair of gloves before you sharpen the teeth on that chainsaw.

Filing The Teeth of a Chainsaw

Filing a chainsaw is not that simple. There are many things to consider.

You don’t have to use the same number of strokes on each tooth on each side when you sharpen a saw. Rather, you should focus on removing the same amount of metal every time you file.

Any chainsaw that has been hand-filed could have a side where the teeth are a little longer or shorter than the other. Unless you spin the saw around to sharpen the other side, you will likely end up that way. This is because you will have a stronger filing (more metal removed) on one side than the other, unless you spin the saw, or walk around to the other side of the bar to do the other side. It is harder to sharpen from your weaker side, without moving. This means that the side of the saw that you stood on for your weaker filing stroke, will have longer teeth than the stronger side will. Well, that’s how it’ll end up if you simply count the number of file strokes anyway. The alternative is to move to the other side, or spin the saw, to sharpen the other side. So, when filing your chainsaw teeth, ensure the same amount of metal is taken from each side.

When sharpening a chainsaw with a file guide, though the instructions may tell you to rest the file guide on the tooth and run it against the depth gauge every time, this may actually cause undercutting of the teeth. Instead, lift the file up off the tooth on the the back stroke, especially when the teeth of your chainsaw are somewhat messed up.

How to Sharpen a Chainsaw With a Round File

Got a chainsaw sharpening file the proper diameter to fit the curve of the teeth on your chainsaw? Yes? Okay, ready to go. If you don’t have one, then go to the store that sold you the saw, or to the hardware store and get a proper sized round file.

The first thing you want to do is make sure the chainsaw is secured in a vise. This can either be a stump vise or a bench vise (for the bench vise, it has to be on a flat surface). Make sure to clamp the vise onto the middle of the bar, the
strongest point. Don’t clamp on down by the edge where the chain is.

Next, mark your starting spot. This is the first tooth you sharpen. A visible mark will let you know when you have done all the teeth on one side before turning the saw around to get the teeth facing the other way.

Third, the file guide should be placed over the cutter. The round file should then be put across the file guide. Making sure you use full strokes, draw the file from the inside of the cutter. This ensures that you sharpen all the teeth on one side of the chainsaw before you do the same on the other side. Slide the file angled across the face of the cutting tooth, using a moderate twisting motion to discharge metal filings.

Push the file from the short side of the angle toward the long point. This should leave a smoother cutting surface.

Filing Depth Gauges to Even Height

The clearance between the depth gauges (rakers) of the chain and the teeth becomes smaller the more you sharpen the chain. In order to balance out the reduction, you may need to file the depth gauges as well. There are sharpening guides that will do the teeth as well as the depth gauges. Unless you have one of these, you will need to separately file the depth gauges. Rakers determine the amount of wood that the cutter will remove on each pass. They should be equal.

Put the filing guide over the chain, with its top surface resting evenly on the top plates of the chain. Use a flat file to stroke the cutter from the inside to the outside, making sure the depth gauge is washed out. This process should be repeated over and over until all the depth gauges are of the required height.

Here’s a pretty good picture explanation of the chainsaw sharpening process at Wiki-How that you can follow.


A sharpened chainsaw will instantly make your work a lot easier. All teeth and depth gauges being equal will also make better cuts.

Sharpen your chainsaw teeth more frequently than just when there’s sawdust present.

When hand sharpening a chainsaw with a file, read the manual, know the angle recommended for the file strokes, wear gloves, secure the chainsaw to prevent movement, ensure that depth gauges are all equal height, use a file guide.

Don’t just count strokes of the file, remove the same amount of metal on each tooth, and from both sides of the bar. Look for teeth that are a little bit longer or shorter.

Depending on the amount of work you have to do, the chain-sharpening process may have to be repeated to suit your needs.

Lastly: After sharpening chainsaws, check chain tension, and soak with oil. Click here to get new chain or parts for a chainsaw, like chains, adjusters, oil, and other stuff. Go cut some wood!


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