How to Sharpen a Chainsaw

A sharp chainsaw cuts well without the need to force it through the material. If your chainsaw is dull, it likely rides in the cut without actually cutting it much further. Also, make sure to check the waste material from your saw. Dust means it needs sharpening while chips indicate that it is still sharp.

If you’re planning to sharpen your chainsaw by hand, there are a few tools you need. The two most important are a round file to sharpen the cutters and a flat file for the depth gauges. You should also use a file guide to hold the round file at a uniform depth and a depth-gauge guide for lowering the depth gauges. Your round file should match the diameter of your cutters. Do not use a rattail file on your chain. Its tapered shape and coarse teeth will damage your cutters. While you may not use them while sharpening, gloves can help prevent injury when advancing the chain.

Before you sharpen your chainsaw, you need to decide how you’re going to do it. You could do it by hand with a round file or you can use several different tools. The hand file is the least expensive option by far, making it the best choice for casual users. As you use your chainsaw more and your desire to save time sharpening increases, you can look into the more expensive, but more efficient, options.

When sharpening a chainsaw, the most important thing is uniformity. Before you start the sharpening process, secure the saw in a vice to keep it stable. Make sure to engage the chain brake, as well. If you don’t have a vice, you can cut a two-inch deep groove into a log or other sturdy piece of wood.

Start by placing the file and file guide into a cutter near the end of the chain, marking the area with a marker so you know where you began. Line up the file with the factory-ground angle, which is usually between 30 and 35 degrees. Make a stroke and stay parallel to the ground, moving away from your body. Make up to six strokes, keeping track of how many you used. Continue sharpening using the same number of strokes, skipping every other tooth. Once you sharpen a few cutters, release the chain brake to advance the chain. After you’ve finished one direction of cutters, go back and sharpen the cutters you skipped.

If you feel that sharpening your chainsaw by hand takes too much time, you may want to use a rotary tool with a sharpening attachment instead. Tons of chainsaw sharpening options exist, each with different diameters of grinding wheels. Place the wheel against the cutter, keeping the metal guide parallel to the factory-ground angle. Count to four and sharpen the cutters, just as you would with a file. As you get better at sharpening with a rotary tool, you can leave it on between cutters.

Use the depth-gauge guide to check the height of the depth-gauge fins in front of the cutters. Most gauges rest on the cutters, straddling the depth-gauge fin. If the fin is taller than the guide’s ledge, lightly file it with the flat file. Avoid using too much strength, otherwise, you’ll file off some of the guide.

If you’re a person who uses their chainsaw year-round, sharpening your saw can consume a significant amount of time. By investing in a bench-mounted sharpener, you can cut down on the time it takes to sharpen your chainsaw and get more accurate results. This can even extend the life of some chains because the sharpener makes it almost impossible to grind away too much material.

After sharpening, if your chainsaw pulls to the side when cutting, the cutters on that side are sharper than those on the other. This is why sharpening a chainsaw requires extreme uniformity. If your chain is catching or kicking back while cutting, you haven’t sharpened the cutters enough. When sharpening, you may notice nicks or cuts from contact with rocks or objects in trees. These can be extremely difficult to work with and you may need to see a professional.

When in doubt, take your saw to a professional. Chainsaws can be extremely dangerous and improper sharpening can increase the risk of injury. Additionally, pros have access to tools, equipment, and experience that dramatically increase the quality of the sharpening job. Plus, it takes significantly less work. Having a professional sharpen your chainsaw can also be much less expensive than other options if you don’t need to do so regularly.