How to Sharpen a Chainsaw | Do It Safely & Efficiently

Keeping your chainsaw chain in top condition will not only help your chainsaw have a longer life, but it’s also very important for safety reasons. A dull chain can actually be far more dangerous than a sharp chain.

Dull chains cut slowly and rub against the wood rather than cutting through it, increasing the risk of kickbacks or pinching. Also, continually cutting with a dull chain can eventually damage your chain, or the entire chainsaw, beyond repair. Read further as  Garden Aware  chainsaw experts will offer valuable advice on how to sharpen a chainsaw so you can be safe and not have to buy a new one.

How to Sharpen a Chainsaw Safely and Efficiently

Learning how to sharpen a chainsaw blade is important so you can keep your chainsaw cutting efficiently and safely. It also saves you from having to pay someone to do it, which can get costly.

Things to consider when it comes to sharpening a chainsaw chain:

  • Know when it’s time to sharpen.
  • Don’t let it go too long without sharpening. Do it as soon as you know it’s time.
  • Understand the anatomy of your chain so you know what needs sharpening.
  • Know how to check and/or adjust gauge heights.
  • Know the proper tools to use (and not use).
  • Use the proper angle for each of the cutter teeth so they’re all sharpened equally

Here are the steps involved in sharpening a chainsaw chain. You’ll see some of these discussed in depth throughout the article.

  • Know the diameter of the cutter teeth so you know what size file to buy. Some sharpening kits will come with two or three different sized files, so make sure at least one of those will fit.
  • All of the cutting teeth need to be the same height, so inspect the cutters and start with the shortest one first, then file the rest to that height.
  • To prevent movement while sharpening, you’ll need to secure the chainsaw. You can use a pinch vise or anything else that’ll keep it in place while you work.
  • Set the chain brake, and only release it when you need to advance the chain.
  • If you’re unsure about the angle to use, check the manual and use a file guide.
  • Check the depth gauge height and adjust if needed

Dull Chainsaws are Slow and Dangerous

The effectiveness and efficiency of chainsaws is what makes people buy them. The sharper, the easier they cut through the wood. Sharper also means safer for chainsaws, as a dull chain can cause many hazardous issues.

If you buy a chainsaw and right away it cuts slowly, you have a defective chainsaw and should take it back.

One danger of a dull chain is the bar getting stuck in the wood while the motor is still running, which can lead to the motor burning out. If that happens, you need a new chainsaw. Dull blades also increase the risk of hitting something in the wood and kicking back to the operator.

Even a dull chain can do some serious damage if it hits you in the head or neck.

When to Sharpen

There are various signs you should look out for that will indicate your chain is dulling. Once you are aware of the issue, you should take care of it immediately.

  • Slow cutting or resistance: If your chain is sharp, it requires very little force to cut through wood, even thick trunks. A dull chain will slow it down, and there’ll be more resistance as the chain isn’t actually cutting through. If you must use more pressure to get the chainsaw through the wood, it’s probably because your chain is dull.
  • Check your sawing waste: Normal, sharp chainsaws produce large chunks and woodchips while you’re sawing through trees and logs. If you instead find super fine sawdust, your chain needs sharpening.
  • Crooked cuts: Sharp chainsaws cut evenly, while cuts from a dull chain will be uneven and crooked.
  • Noise or rattling: Engines are already loud, but if you start to hear any rattling or the engine is just louder than usual, then it’s probably straining from the chain teeth being dull.
  • Smoke: Creation of smoke could be two things: Your chain isn’t lubricated enough, or the chain is dulling. Check oil levels first and if all is fine there, your next step will be to sharpen your chain.

Chain Anatomy

Just as doctors and nurses need to understand human anatomy before taking care of patients, knowing the anatomy of your chainsaw’s chain is important when it comes to sharpening it. There are two areas in particular that you need to be able to identify: the parts that you sharpen, and the parts that help you keep track. But you should also know what the other pieces are and what they do.

A chainsaw chain is made up of three basic pieces:

  • Cutting tooth
  • Tie strap
  • Drive links

The cutting teeth on your chain is what needs to be sharpened. They are the semi-circular edges you see on either side of the chain. Usually every other edge faces left, while the others face right. Cutters also come in different shapes and sizes, depending on the type of chain: round tooth, square tooth semi-chisel, and square tooth full chisel.

The part of the cutter that looks like a shark’s fin is called the depth gauge. This will normally be a bit shorter than the cutter, which helps to guide how far into the wood the blades cut. This can be adjusted overtime (more on that below) as the chainsaw is used more.

The other fin-like pieces are the drive links that help move the chain around the guide bar. On the sides of the drive links are identification numbers, which some people will use to know where they started and where to stop when sharpening.

The tie straps are the rectangular pieces that tie the drive links together when there isn’t a cutter tooth in place.

The teeth on a chainsaw chain can be spaced differently depending on the type of chain it is. For your purposes, your chainsaw chain is probably a full complement, meaning there’s as many teeth as possible on the chain.

Tools for Sharpening

There are many kits you can buy with special tools for sharpening your chainsaw chain. If you don’t want to do it by hand, you can easily learn how to sharpen a chainsaw blade with an electric sharpener.

Likewise, you can find out how to sharpen a chainsaw with a Dremel. 

For manual sharpening, your main tool for your chain’s cutters will be a round file that is the same diameter as the cutter. You’ll also need a flat tooth file for adjusting the depth gauge, along with a guide to measure the depth gauge height.

Be sure NOT to get a rattail file as it has uneven diameters and could sharpen your cutters unevenly, making your problem worse instead of better.

Sharpen Your Chainsaw to Manufacturer’s Recommendations

As with any tool or device, it’s always a good idea to look at the manual for your chainsaw. This is especially true for sharpening the chain, as you want to make sure to sharpen it to the manufacturer’s recommendations.

If you second-guess what they’ve put in the owner’s manual and decide to do your own thing, you could seriously damage your chainsaw’s chain, or make it even more dangerous to use.

Check Depth Gauge Heights

cut woods

Use the depth gauge guide to determine how high the depth gauge is on your chain. The manufacturer’s recommendations will tell you how high it has to be in reference to how high the cutter is.

Every time you sharpen your chain, you want to check the depth gauge height to make sure it’s not too high. If the distance between the two is too short, use the flat file to file down the depth gauge.

Once the two are filed down to the point where they’re level, or there isn’t much distance between the two, it’s time to buy a new chain.

File at the Right Angles

To ensure that your chain continues cutting evenly and effortlessly, when you’re sharpening the cutters it needs to be done somewhere between a 30-40 degree angle, depending on the type of chain. It’s important that you use the same angle for every cutter on the chain.

Some newer chains might mark the top of each cutter with a thin line, going in the direction of the proper sharpening angle. This is handy for beginners sharpening their chainsaw for the first time.

An easy way to keep the angle consistent is to learn how to sharpen a chainsaw with a file guide. If you’re using one of these, make sure the arrows on the guide are pointing in the direction of the chain’s rotation. Do this and you’ll sharpen each cutter at the right angle.

Sharpening by Hand

Sharpening a chain by hand may seem like a tedious task, but if you do it right it should only take you about 10-15 minutes.

sharpening a chainsaw can take about 10 to 15 minutes

Not only do you need the appropriate tools, but you need to also use proper safety precautions.

This may be common sense, but it needs to be pointed out that the chainsaw should be off and not running while you’re sharpening the cutter.

That said, wear gloves while you’re handling the chain and the bar and protective eye wear.

Clean the chain of any dirt, oil, or grease to prevent buildup on the file, and make sure the tension on the chain is correct.

After all that, before you start filing, inspect the chain for any damage. If the cutters are just worn down from use, you should be fine. But if any of the teeth are damaged in every way, you might need to hire a professional or buy a new chain.

Once you’re good to go, work on only one side of the chain at a time. As mentioned before, the cutters one each side of the chain face in different directions. This also means that the cutter on the left side is going at an opposite angle as the one on the right side.

If you start working on the left side first, keep working on the left side to keep your angles consistent until it’s done. Then switch and work on the right side.

Leave the chain brake on while you work so the chain stays in place. Release it only when you need to advance the chain to expose new teeth to be sharpened. This is where having your gloves will come in handy.

If you don’t want to sharpen your chain by hand, try looking for the best electric chainsaw sharpener.