How to Sharpen a Chainsaw
Updated: Jun. 11, 2024
A dull chainsaw chain is difficult to use and also inefficient. Here's how to tell if yours is dull, and how to properly sharpen it up.
Time
15 to 45 minutes
Complexity
Intermediate
Cost
$50 to $100
Introduction
It's tempting to push a dull chainsaw chain farther than you should to avoid the time and hassle of sharpening it. But at best, that just makes it harder for you to get through the next log. At worst, it means damage to your saw and even injury to yourself from trying to muscle it through the job.
Here's how to sharpen a chainsaw chain, how to tell if yours is dull, and when it's time to call a pro.
When Is It Time to Sharpen a Chainsaw?
A sharp chain produces large, chunky, curl-like wood chips. If it's instead producing fine sawdust, then it's time to sharpen the chain. Other signs it's time to sharpen include:
- If it cuts unevenly, pulling to one side,
- If it takes extra effort to cut through wood, and
- If it smokes while cutting.
"If your chain is oiled and you've checked the tension on your chain to ensure it's not too tight or too loose and it still produces fine powder or smokes, then there's a good chance that you're cutting with a dull chain," says John Allen, product manager at STIHL, Inc.
Methods of Sharpening a Chainsaw
To sharpen a chainsaw chain, you can use either a handheld file or a bench grinder.
Handheld File
The cheapest method is using a hand file to sharpen each tooth on the chain. "It's also the most challenging and slowest, due to the difficulty of maintaining correct angles, depths and consistently filing each tooth," says Allen.
To make it a little easier, use a chainsaw 2-in-1 file guide, which simultaneously sharpens the cutters and sets the depth gauge.
Bench Grinder
An electrically powered bench grinder, aka chain grinder, is what most pros use to sharpen a chainsaw chain. "This option is fast, repeatable and precisely sets the angles back to factory settings; however, saw chain grinders can be expensive and are typically only found at dealers," says Allen.
Safety Precautions
While sharpening a chainsaw chain, always wear safety glasses and cut-resistant gloves. If hand filing, secure the chainsaw to your bench with a stump vise. If using a grinder, be wary of overheating the chain. Beyond that, "Sharpening the chainsaw chain is the safest part of the very dangerous task of running a chainsaw," says master arborist Lisa Tadewaldt.
When to Call a Pro
Even for those who enjoy DIY, hiring a pro to sharpen a chainsaw is common. That's because it's relatively inexpensive, it saves time, and it often delivers a better-quality sharpen than can be achieved with a hand file.
How much does it cost to hire a pro?
Professional chainsaw sharpening usually costs between $10 and $20, or about one-third to one-half the cost of a chain.
"Once you factor in the time it takes to do it, it really doesn't save you much money to sharpen it yourself," says Tadewaldt. "People who sharpen their own chains do it for other reasons, like it can be done on-site while working, to keep cutting without needing extra chain."
Tools Required
- 2-in-1 file guide (optional)
- Depth gauge
- File guide bar
- Flat file tool
- Permanent marker
- Round file
- Stable workbench or other hard surface
- Stump vice
Project step-by-step (6)
Prep the work area
- Wear safety glasses and leather cut-resistant gloves.
- Secure the chainsaw to your bench with a vise or to the log using a stump vice.
- Clean the chain. Check it for damage and ensure you haven’t yet reached your wear marks (if you have, replace it instead of sharpening it).
- Start with the tooth that has the most wear, aka the master tooth, and mark it with the permanent marker so you know where you started.
Pro tip: Ensure you use the correct file size to match your chainsaw’s saw chain. Also, if you tension the chain a bit, it will make everything easier.
Sharpen the chain
- Use the round file and filing guide bar to file the left-side cutters.
- As you go, check that each tooth is straight and sharp, then move to the next one.
- Repeat until all are the same size, then sharpen the saw chain on the other side.
- Guide the file by applying even pressure, keeping the file at 90 degrees to the guide rail and stroking it in a forward motion, applying pressure from the inside to the outside.
- Only sharpen on the forward stroke, then lift the file off to move it back.
- Regularly rotate the file, so it wears evenly.
“How you hold the file and how deeply you file are critical to the saw chain’s performance,” says Allen. “Three strokes should be sufficient however a really dull chain may require more.”
Check your progress
- Check for light reflecting from the cutting edge. If you see any, that means the tooth needs more sharpening.
- Make sure all blade teeth are the same length as the master tooth.
Adjust the depth
- Once all of the teeth are sharp, check the depth gauge setting by setting the filing gauge over the chain. Make sure to use a gauge designed for your chain’s pitch.
- If the depth gauge protrudes past the filing gauge, you’ll need to make adjustments using the flat saw chain file.
- File the depth gauge horizontally until it is flush with the filing gauge. Make sure the depth gauge isn’t too low or it will increase the risk of chainsaw kickback.
“The angle and depth need to be consistent. Keep monitoring the depth gauges and make the required changes, as cutting efficiency is affected due to uneven filing or not adjusting depth gauges,” says contractor Jay Sanders.
Pro tip: Use a 2-in-1 file holder to simultaneously sharpen the teeth while resetting the depth gauge to the correct height.
FAQ
How many times can you sharpen a chainsaw chain?
It depends on the materials you’re cutting, your cutting technique and how well you clean and maintain the chainsaw. Generally, you can sharpen a chainsaw between three and 10 times. There are laser markings on the chain that indicate how far you can file it back. Once you reach those, it’s time to get a new chain.
How long does a chainsaw last?
If you only use your chainsaw periodically, a chain can last for decades. For those who use their saws on a daily professional basis, a chain might only last a couple of months. It also depends on your cutting technique.
“A beginner will go through the chain faster, but for a homeowner who is experienced and uses the saw semi-frequently on the weekend, a chain can last multiple years,” says Tadewaldt.
How do you maintain a chainsaw?
Regular maintenance will extend the life of your chainsaw and your chainsaw chain.
- Regularly lubricate the chain using a good-quality chain lubricant.
- Check the chain tension often, to ensure it’s not too loose or too tight.
- Sharpen the chain regularly, using the correct tools.
- Never force a dull chain to cut.
- Clean it before storing, leaving the chain lubricated.
- Avoid hitting abrasive materials while cutting, like dirt and rocks.
“The biggest thing a beginner can do to avoid dulling their chain is to keep the chain out of the dirt,” says Tadewaldt. “It is common when learning to cut to accidentally put the chain in the dirt, which immediately dulls the chain.”
About the Experts
- Lisa Tadewaldt is an International Society of Arboriculture board-certified master arborist. She has worked in residential tree care in the Portland, Oregon, area for the last 24 years, and is the founder and owner at Urban Forest Pro
- John Allen is a product manager at STIHL, Inc. where he is responsible for all professional chainsaws, industrial products and their accessories. He has worked for STIHL, INc. for 18 years and his favorite chainsaw is the fuel-injected STIHL MS 500i.
- Jay Sanders is a licensed contractor based in Baltimore. He owns Maryland Contractor and Castle Dream Construction, and has been working in construction for more than a decade.
Originally Published: November 02, 2020
