How to Sharpen Chainsaw Chain

On our Lawnmowerpros.com Facebook page, Dennis F. asked the following:

“Chainsaw chain, bars, and the correct way to sharpen them.”

Quick, concise and to the point. We like that. Thanks Dennis.

Well, you heard the man! So let’s jump right into your chainsaw chain and how to keep it sharp.

If your chainsaw chain was forged in the depths of the Misty Mountains, and anointed with elven magic to ensure that the blade will never grow dull, then it is a mighty weapon indeed.

For the rest of us schmoe’s, you’ve got a run of the mill chain that’ll dull faster than you can say “My precious”.

So I guess we should start with how to figure out when it’s time to sharpen.

There are subtle indications of this, namely the consistency and size of the cuttings. A sharp chain will leave cuttings that are 1/8″ to 1/4 in length with a slight curl. If your wood cuttings are smaller, with the consistency fluff then it’s probably time to sharpen the chain. And, of course there is the fact that the chain won’t cut any more.

That’s a good one too.

Here’s a nice saying that kind of brings it all together:

For most woods, you’ll be able to press the bar into the wood and it will pass through smoothly without requiring you to move the bar around. If you find yourself having to rock the bar back and forth or move it around from angle to angle… it’s definitely time to touch it up.

So the next logical question is:

How often will I need to sharpen it?

That can depend on several factors:

Wood Density

Without getting too far into the whole Janka Rating system for wood hardness, we do know that in North America, there are several types of wood that require over a thousand pounds of pressure to mar:

  • Hickory
  • Pecan
  • Hard Maple
  • White Oak
  • Beech
  • Red Oak
  • Yellow Birch
  • Green Ash
  • Black Walnut
  • And of course, everyone’s favorite chain killer… hedge wood.

Of course, chainsaw chain is made of tempered steel, but when you run it through something as tough as black walnut, it’s going to dull in record time.

Dirt

I’ve said it a million times. Dirts causes troubles. Digging the tip of your chainsaw bar into soil is one of the fastest ways to dull your chain. Why? Because it’s sand. Some sandier than others, but it all has silica in it and that’s sand. Sand Sand Sand. And sand dulls stuff. It’s a scientificky proven fact. If you have to move dirt to get to the wood, use a shovel.

Don’t believe me? Don’t care. I’m right.

Saw Abuse

Forcing the chain through the wood, pushing at extreme angles, striking chain-link, concrete, whatever. All of these should send you to the corner for an hour. Each of these alone can expedite the dulling (or damage) to your chain not to mention flirting with a serious case of “Kickback“. The only shame in admitting you don’t know what your doing is when you do it in the emergency room. Know your machine!

Chain 101

Before we dig into how to sharpen the chain, here’s a few basics for the novice (that’s french for “new guy”):

chain parts

Drive Links are the part of the chain that connects with the chain sprocket, which causes the chain to move along the length of the bar.

Cutters are the blades or the part of the chain that does the actual cutting.

Chain Pitch defines the size of the chain. The drive sprocket must be the same pitch as the chain, and so must the nose sprocket in sprocket-nose bars.

Chain gauge is the drive link’s thickness where it fits into the guide-bar groove. The gauge of the chain and the gauge of the guide bar must match.

Lugs are the rivets that connect all of the chain components together.

Tie Straps are the links that connect the entire assembly. These are fastened together with the Lugs.

Depth Gauge is the part of the cutter link that determines how deeply the cutter will cut.

EVERY GIRL’S CRAZY BOUT A SHARPENED CHAIN!

For this job, we recommend the following:

safety glasses

Eye protection

work gloves

Work Gloves

bench vice 

A bench vise or a filing vise

a sharpie marker

hand files

Bar Sharpening File and a Flat File

Bar Filing Plate (optional)

 

THE BEGINNING IS A GOOD PLACE TO STOP

Pretty please…with a cherry on top…Turn off the dang saw! Yeah, it’s common sense but common sense is anything but common. So, go on and shut it off. Last thing I need is a bunch of angry, three fingered emails pointing out how I didn’t mention to turn the saw off.

LOCK ER’ DOWN

Next, we’re going to secure the bar. If you’re in your shop and you have access to a bench vise, that’s the way to go. Secure the bar in the vise, making sure that the vise is gripping at the center of the bar. Too far towards the top or bottom of the bar can cause the chain trough to bend in…and that’s bad.

If you’re out in the field, I highly recommend an Oregon Bar filing vise. This little nugget can be hammered into a fallen tree or stump and it works just like a bench vise. it’s simple and rugged and will pay off in the end.

Purchasing an Oregon Bar Filing Vise for yourself and make life a little easier.

WHERE TO BEGIN…

As my Grand Dad used to say, just pick a spot and start swinging. But unless you want to spend the next two hours just going round and round, you’ll want to mark your beginning point. A white paint marker will work just fine, but any indelible marker will work just as well provided the link is cleaned off. Remember: ‘marker’ don’t mark so well on oily surfaces.

CHOOSING A FILE

When hand filing your cutters, it’s essential to have the correct file and believe me when I tell you that once you start filing, you’re going to wish you had picked up that little wooden handle as well.

Generally, we see three sizes of hand file:  7/32″, 5/32″ and 3/16″. So, how do we know which one to choose? Well, our friends over at Oregon had this to offer:

filing guide instructions

When hand filing, it’s important that 1/5, or 20 percent, of the file’s diameter is always held above the cutter’s top plate. Using the correct file guide is the easiest way to hold the file in this position.

Having said that, they have simplified the process by offering sharpening kits which include the hand file and a filing plate (which reduces the chances of error).

TIME TO GET STARTED

Place the file in the cutter recess (that’s the curved part of the cutter).

Run the file away from you, engaging the entire length of the file. Make a clean, complete pass.

Remove the file and return it to the start position and repeat.

sharpen cutters

Sharpen cutters on one side of the chain first. Then turn your saw around and repeat the process for cutters on the other side of the chain.

3-4 passes on each cutter should be adequate.

SETTING THE DEPTH GAUGES

When you look at a new chain, you’ll see that the top of the depth gauge is just under the top of the cutter.

Driver one

When the cutters wear down, the top of the cutter will shorten, effectively lowering the cutter edge below the depth gauge.  to match or exceed the height of the cutter.

Driver two

So, when we sharpen the cutters, we may need to drop the height of the depth gauges as well. This is where your flat file comes in.

I’m telling you now, just go ahead and get yourself a depth gauge tool. This is going to free up time and improve chain performance. They’re affordable and easy to use. You’ll thank me.

Here’s a tutorial from Oregon that breaks it all down for you:

FINAL INSPECTION

Before firing that bad boy back up, it’s a good idea to inspect the chain for:

Cutter Length: Check the length of each cutter for uniformity. Anmeasuring cutter
adjustable wrench is a great way to measure the length of each cutter quickly.

Appropriate Chain Tension: “It’s weird. When I bought the chain, it fit just fine. Now it’s sagging.”

Turns out that links can stretch. Your chainsaw has a chain adjuster which will allow you to adjust for slack although excessive wear may require removing a link or replacing the chain entirely. Once adjusted, the chain should fit snugly within the guide bar trough but should not resist movement.

Rust or Corrosion: Most can be cleaned off with a little gasoline and a steel brush. The links should bend and move freely. Never use a corroded chain that resists movement! And always remember to oil your chain before re-installing it.

Bending: Here’s how it goes down. The chain gets a little dull and all of the sudden we’re cranking that bar back and forth, side to side. Or… We’re cutting a limb or a log and the wood pinches the chain. It happens. Don’t sweat it. But when it does, it’s a good idea to inspect the chain. They bend, they wobble and you don’t want that thing flying off of the guide bar while it’s in motion!

A bent chain should be replaced immediately.

danger

Never use a bent chain!

Chipping: Closely inspect cutters for chipping. Some chips can be filed out, while others require replacing the chain.

Damage to the guide bar: Hand spin the chain a few times to ensure the guide bar trough is not bent or binding up. If it is, there’s a reason for it.

Given the potential for injury, we don’t recommend trying to repair your bar. 

danger

When in doubt, take it to a technician for a second opinion.

 

And that’s it. That’s pretty much the whole thing.  Friction = heat = expanding metal so make sure to Lubricate the chain well.

Give her a spin and you should be good to go.

Until next time.

-Bill

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Summary
How to sharpen chainsaw chain
Article Name
How to sharpen chainsaw chain
Description
Learn the proper way to sharpen a chainsaw chain and what tools are required.
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Publisher Name
LawnMowerPros
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Bill Brown

Bill Brown

Bill is the head of content creation for the LawnMowerPros Blog and DIY section. He’s been in the Outdoor Power Equipment Industry for years and he’s still learning new things everyday. You can often find him creating featured articles, DIY guides, videos, graphics and much more.