Keeping your chain sharp is one of the most important parts of maintaining a safe and functional chainsaw. A dull or worn chain can get caught in wood, kicking the bar up into the air, one of the most frequent causes of chainsaw related injuries. Chainsaws are powerful and heavy tools that need to be taken proper care of, or else bad things can happen. Plus, not only are they an enormous safety hazard, but a worn-out chain will make your motor work harder and eat up more gas. It’s unsafe, it’s wasteful, and it ruins your tool. Don’t skip out on sharpening your chainsaw blade after regular use.
You can sharpen your chain with a file or an electric chainsaw grinder. If you have a square chain for big trees, there’s a special method for your chain called square filing.
When to Sharpen the Chain
A good rule of thumb is to sharpen your chain every time you put fuel into the chainsaw. You can tell if it’s time to sharpen if the saw starts to cut more slowly and starts throwing more dust rather than wood chips. If you have to force it, you probably need to sharpen it.
Equipment for Chainsaw Sharpening
Let’s start with the safety gear. As with any project involving sharp tools, you’ll want to wear gloves and eyeglasses even though you might not be cutting anything. Filing and sharpening can result in unexpected shrapnel finding its way loose from a worn blade, and it only takes one eye injury to cause life-changing damage.
Also, avoid wearing loose-fitting clothing or any jewelry. Even though the saw isn’t running, these things can snag in the chain and become damaged or even cause injury.
You’ll also need a chainsaw filing kit with a round file, a guide, and a device called a depth gauge measuring kit. Your chainsaw’s manufacturer can tell you about the angle you’ll sharpen to. You can typically find this information online if you don’t still have your owner’s manual. It’s also commonly found on the chain’s packaging.
Note: It’s important that you have a proper round file for chain sharpening. Do not use a rat-tail file as its tapered angle and rough grade will destroy your cutters.
Understanding Your Chain
There are three parts of your chainsaw blade that you’ll sharpen. There are semi-rounded edges that can be easily and quickly reshaped with a file. There is a piece called the depth gauge that looks like a small shark fin. This is what determines how far your chain slices into the wood. The angles of the pieces keep the cutters moving in a straight line.
Once the cutters start to wear down to the height of the depth gauge, you can still get some life out of your chain by filing down the depth gauge with a flat file and the guide included in your kit. Take a close look at the cutters before you file, however. If they are nicked or warped, filing them won’t improve the chain’s ability to cut. At that point, you’ll need to get a new chain instead.
It’s important that you file at the correct angles, otherwise, you’re just going to ruin your sharpeners and need a new chain. Put your round file into the file guide and hold the file at a 30-degree angle to the chainsaw bar. It should be at a right angle vertically. Begin filing while keeping track of the number of strokes you use. It’s important to file each cutter or depth gauge the same number of times to ensure even wear and consistent performance.
To file properly, you’ll use an outward motion away from your body. The guide is designed to keep the file in place while cutting all of the teeth to the same shape and depth. To easily support the saw bar before sharpening, cut it into a log to hold it in place.
Using a Power Chainsaw Teeth Sharpener
While sharpening by hand is a critical skill, you can save a lot of time by using a rotary chainsaw sharpener. These are easy and safe to use, but you still want to be sure to take the safety measures discussed above.
To use your chainsaw teeth sharpener, simply press the grinding wheels against each cutter with the metal guide piece parallel to the provided angle, and turn on your sharpener. Apply a sideways motion and count to four as you move across the sharpener. Do this on each one with the same amount of pressure at the same angle to achieve a smooth and consistent sharpening and wear pattern on each one.
Whenever you notice that the depth gauges stick out above your guide, you know it’s time to file them down. Even with a power chainsaw teeth sharpener, it’s still recommended to work on the depth gauges by hand with a flat-file and your file guide. This will help you achieve the most consistent results and get the longest life out of your chain.
Important Tips about Chain Sharpening
At best, you can sharpen your cutters about 10 times before you need to replace the chain. However, if you’ve messed up your chain after just a few sharpenings, a technician who does sharpener work can often machine them back into the correct shape.
Keeping the same chain on your saw for too long can cause issues with the sprocket bar. For best results, it’s a good idea to regularly rotate between three or more properly-sharpened chains to avoid damaging your tool.