How Are Chainsaw Rakers Measured? (With 3 Brand Examples). Chainsaw depth gauge tool

Saw Chain Maintenance Sharpening

(Note: This is Part 2 of my Chainsaw Basics Series. In Part 1 entitled ‘How Saw Chain Works‘, I went into all the terminology and the concepts of what saw chain is and how and why it works. Check out Part 1 here if you haven’t already.)

Maintenance vs. Sharpening

There is a reason I talk about chain maintenance as opposed to just “sharpening a chain”. In my experience, I have found that anyone can grab a file and scratch the teeth and come away with something that is sharper than when they started. You don’t necessarily need to even understand what you’re doing to be successful. If you don’t really understand the concepts involved, you may be able to get away with this a few times on any individual chain. That’s how I did it for my first few years. I saw other guys filing chains and I said “I can do that”, and I just grabbed a file and started going at ‘er.

The real skill however, comes with being able to take a chain through its entire lifespan, from brand new, all the way down to nothing left, and have it cut efficient and properly the entire way. That requires real knowledge of the underlying concepts. So when I say ‘sharpening’ I am referring to a single occasion where saw meets file, and when I say ‘chain maintenance’ I am referring to the series of individual sharpenings that take a chain through its entire service life.

Another thing I’ve found is that you will get the best results if the sharpening on any one chain is always done by the same person. I find that different people working on the same chain over time gives really inconsistent results.

All of the chain that you will be working on is called “round ground” which means that it is sharpened using round files. You can also maintain these chains using a machine grinder, but that is beyond the scope of this article. I have always preferred hand sharpening using files. I find that using files forces me to slow down and really FOCUS on each individual tooth, and it requires me to fully understand how chain and cutters work. So, for learning purposes and for general skills in the field, hand sharpening is superior.

Sharpening Kit

A note on files – the files that you use MUST be high quality, they DO have a lifespan, and they MUST be kept rust free. So this means, buy good quality files, preferably from a dealer; take care of them; and do not allow them to be exposed to water, because once they rust, their working days are done. And even if you take care of them, they will eventually lose their bite and need to be replaced.

For a filing kit being used in the field, I recommend having at least 2 files of each size on hand. Its the old rule of redundancy: 2 is 1, and 1 is none.

A note on file handles – like I say, files have a lifespan, they don’t last forever. So I greatly prefer a removeable type file handle such as this one, as opposed to having a bunch of regular old-school handles. This way I only need a single handle for my entire kit. You pop the file in, use it, and pop it out. This keeps my kit nice and small.

For the best results with sharpening, you are going to want a vise. At the shop, a good solid bench vise is perfect. In the field, you can use a stump vise, or a truck mounted vise, or a vise mounted to a piece of equipment. I have seen them mounted to bucket trucks and chippers, among other things. Yes, you can sharpen a saw without a vise, but it’s not nearly as easy or enjoyable.

Bench Vise	Stump Vise

File and Chain sizes

There are basically 3 sizes of saw that we use, and each has its own size chain which uses its own size file. I won’t get into the measurements of chain pitch and gauge here, but basically we use small saws for aerial work, such as the MS200, we use medium size brushing saws, such as the STIHL 26 or Husky 346, and then we use larger saws, like the Husky 575 with 20″ and larger bars.

So, the 3 basic sizes correspond to 3 different size files. The small chains use a 5/32″ file, the medium chains use a 3/16″ file and the largest chains use a 7/32″ file. Make sure before you start filing that you are using the proper size file for the chain!

One caveat to file sizes is with the larger chain. You can see how teeth are designed to slope backwards, so the more sharpenings they have had, the shorter they get. This is especially significant on the larger chain, which starts out using a 7/32″ file, but once it gets down around halfway, you will actually want to switch to a slightly smaller file, the 13/64″.

The Concept

I find it best to think about sharpening on a tooth by tooth basis. So I’m not working on a chain per se, I’m just working on a single tooth at a time.

For each tooth, the process starts with inspection. The 2 main factors to consider when inspecting a tooth are: the corner and the chisel edge.

The corner must be very sharp for the the saw to cut efficiently. The corner is what starts the cut, and then the rest of the chisel edge carves it out. The corner is usually what gets damaged the most when a sawyer hits a nail or a stone. It can require quite a bit of filing to get back to a nice sharp corner.

The chisel edge is the leading edge of the top plate of the tooth. This is the actual cutter. This edge must be razor sharp. So the act of sharpening a tooth is the process of filing the chisel edge, which in turn sharpens the corner.

The third thing to inspect on each tooth is the raker. I personally don’t even look at the raker at all until the chain is at least half way down. Some people put way too much attention into the rakers and file them down too much, which makes the saw bite in way too hard and makes cutting very jerky.

There is one more definition that you need to know before we get into the technique of sharpening, and that is the Witness Mark. The Witness Mark shows you the proper angle to aim for when you are filing. This is one easy way to distinguish good quality chain. Cheap chains don’t always have a witness mark.

• by following this angle when sharpening, it sets up a good aggressive corner on each tooth, helping the chisel edge to cut efficiently.
• it allows you to get the maximum life from each tooth. Each time you sharpen a tooth, it gets a little bit smaller. Following the angle of the witness mark allows the tooth to last longer. If you were to sharpen a tooth on too steep of an angle, you would end up running out of top plate at the back before you had run out of chisel edge at the front.

The act of sharpening a tooth is the process of filing the chisel edge, which in turn sharpens the corner. It may look very simple if you’ve seen an experienced person doing it, but it is not as simple as just dragging a file over a tooth.

Now as you can see, the cutter teeth are arranged in alternating fashion, one on the left side and one on the right side. This ensures that the chain cuts evenly and straight. So with the saw in the vise, I can only sharpen the one side. When I get done working on all the cutters on the one side, then I will go back through the chain a second time, inspecting each raker and filing as necessary. I will then take the saw out of the vise and turn it around so I can work on the other side.

Sharpening Technique

So, first things first, it is a good idea to wear gloves when sharpening a chain by hand. If you sharpen enough times you will eventually slip, and you can cut your hand pretty bad. Secondly, the chain must be properly tensioned before you start sharpening it. You will be applying pressure with the file – the chain tension must be sufficient to withstand that pressure and keep the tooth from moving. So, like I said, it is best to work one tooth at a time. There will usually be some teeth that need more attention than others. So it is important to really inspect each and every tooth as you go.

Taking your file, fit it into the tooth, and you will see that the chisel edge overhangs the file a little bit. This overhang is how you know that you have the correct round profile on this tooth. Your goal is to maintain this overhang of the chisel edge throughout the life of the chain, never more and never less of an overhang.

The area where I see the most confusion and the most problems is the concept of the round profile. When you are moving the file through the tooth, you are actually grinding every surface that it touches, but it is only the very top section, the chisel edge, that matters. So, to sharpen properly, you must be able to visualize where you are applying pressure with the file.

Proper Round Profile	Proper Application of File Pressure

Consistently applying pressure with the file in the direction shown above will ensure that your sharpening activities properly maintain the correct round profile of each tooth and will allow your chain to cut efficiently throughout its entire lifespan. Countless chains have been ruined partway through their service lives by incorrect application of pressure with the file. Some people push down too much, cutting towards the rivets. Others don’t push inwards enough, leaving the chisel edge with an improper angle, not aggressive enough to really tear into the wood.

Holding the file level, you push all the way through, trying to exactly match the angle of the witness mark. You don’t usually need to apply much pressure with each stroke if your file is good. Applying a lot of pressure takes more material off the tooth and also increases the chances of your hand slipping. With a good file, all you have to do is apply nice, steady, even pressure all the way through. I like to hold the file with both hands: the hand at the back keeps the file level and lined up with the Witness Mark while the hand at the front “pulls” the file through the tooth and applies the inwards and downwards pressure. I will explain more further on in the article about pulling vs. pushing the file when we talk about side dominance issues.

Remember, the file sharpens on the push stroke only. So, coming back, don’t drag the file on the tooth. Just return it to the starting position. If the tooth wasn’t too bad to begin with, just give it a couple swipes and then get down and inspect it. You want the corner to be absolutely sharp, and the chisel edge should be uniformly shiny and sharp.

• Inspect the corner and the chisel edge,
• file the tooth as necessary,
• re-inspect,
• manually advance the chain, repeat the process.

So, continue this process, tooth by tooth, until you have gone all the way around the bar. Some people will mark the starting tooth with a black marker, but I just go by colour. If the groove isn’t nice and shiny, then you haven’t sharpened that tooth yet.

Generally speaking, you are trying to keep all teeth equal size. This is not usually too big of a problem, but if you have hit something serious like a nail, it can be an issue. Sometimes you will have a few teeth with bad corners while the rest of them are not so bad. It doesn’t always make sense to file down all of the good teeth just to match the size of a few bad teeth. In those cases, I just FOCUS on the chisel edge on the bad teeth, temporarily ignoring the corner, and over time, the good teeth will nearly “catch up” to the size of the bad teeth.

Now, this may just be me, but one thing I have noticed with most brand new chains these days is that they are actually ground with a machine profile. I think this means that the manufacturers are assuming that you will be using a machine to sharpen them, as opposed to hand filing. What this means is that the first sharpening with a round file will be as much about establishing the proper round profile as it will be about actually sharpening the chisel edge. So generally, for the first sharpening on a brand new chain, you will need to be pushing a bit harder with the file than normal.

To Recap the Sharpening Process

These are the things to pay the most attention to:

Rakers

So now that you have sharpened each tooth, you can turn your attention to the rakers. As the tooth gets filed down, the chisel edge gets lower and lower, until eventually the gap between the edge of the tooth and raker disappears. At this point, the tooth will not cut, regardless of how sharp the corner and chisel edge are. The standard depth setting for rakers is about half the thickness of a dime, or.025″. Like I say, I don’t even look at the rakers until the tooth is halfway done.

The standard way to check the raker is using a depth gauge tool. The depth gauge tool usually has 2 sides, one is the standard.025″ and the other is.030″, just slightly more aggressive. In practice, you won’t notice any difference between them so it really doesn’t matter which side you use.

So you simply set the depth gauge tool flat on the chain so that the raker rests in the groove. If the raker tip is exposed above the groove, then it is time to file it down. We use a good quality flat file for the rakers, and we always go in the same direction as the filing of the cutters. Raker filing is even more subtle than tooth filing, usually just one simple stroke will do, and rarely do you need to use more than 2 strokes. Whenever you file a raker, you will also want to take notice of the profile of the front corner of that raker. It needs to stay rounded to move smoothly through the wood. So you may need to take a swipe off the front corner with your file as well.

Now in my opinion, the depth gauge tool really only has 2 uses: it is for anyone who is unsure of what they are doing, and it is for people who don’t want to bend down and actually look at each and every tooth. I don’t use a depth gauge tool because I don’t find it necessary. First of all, you don’t need to check the rakers nearly as often as many people think, and secondly, when you have looked at teeth for long enough, you start to be able to see that gap between the tooth edge and the raker. So when I am bending down to inspect the tooth, I am seeing how the raker looks at the same time, and I can tell if I need to take a swipe off of it. One additional option to check your rakers is to set your flat file along the teeth which allows you to see the gap quite easily.

When you file the raker, you will be able to see a couple of straight lines on the top of it. This is how you will be able to tell which rakers you have done.

When you file a saw, you WILL file each tooth, even if it’s just a couple swipes to freshen it up, but you may NOT need to file down every raker on the chain. Do NOT over-file your rakers, you will regret it!

Side Dominance

So, now that you have finished all the cutters on the one side, you can set the file down, loosen the saw from the vise, and flip the saw around to do the other side of the chain. The process on the other side is exactly the same, except that everything is flipped backwards. This is where a lot of people run into difficulty because of side dominance issues. On the one side, you hold the file with the right hand, but when you flip the saw around, you have to hold the file with the left hand. So a lot of people will end up getting a different result on the one side of the chain than they do on the other.

I had to practice for years to overcome this side dominance issue but I think I pretty much have it licked by this point. My main technique for dealing with this is to use my whole body to move the file, as opposed to using just my arm. I can use just my arm on the right side but I find it much more difficult to push with just my arm on the left side. So, I basically try to lock my arm in position at my side and, bending forward at the waist, I use my whole body to move the file and basically just keep my arm stationary. The other thing that I do, as mentioned above, is I try to visualize myself as “pulling” the file, rather than “pushing” it. This way I can do things the same way on the left side as the right. These techniques have helped me to overcome the side dominance issues that are a part of filing chains, and I highly recommend that you experiment to find out what works best for you.

Well, there it is, Basic Chain Maintenance and Sharpening. I know this article is quite long-winded, but I hope you stuck around to the end and that you can get something out of it. Maintaining a chain properly takes a lot of theoretical knowledge of how chain works, and it takes a lot of practice to do it well. But it is very rewarding to be able to restore your chain at any time and have it cutting like new. It is better for your saw, and it is much better on you, the sawyer. The information in these last 2 articles took me years to understand and appreciate – I hope that I can accelerate that process for you.

Climb High, Work Smart, Read – TreeMuggs

I would love to hear from you. Please send all Комментарии и мнения владельцев/questions/hatemail to patrick@educatedclimber.com

Комментарии и мнения владельцев

Great article might be worth making a few videos to complement this. Also the “rakers” is not the proper terminology for chains. As you pointed out at a few points about the relation between the cutter and the “rakers” height difference. The proper terminology is the depth gauge. Raker has been misappropriated from the old two man saws used in the logging industry from years back. They had the similar construction of cutter and raker. In this device the raker was present as a way to rake out the wood debris from the log/ tree while cutting occurred. In the instance of the chain saw the depth gage is present to control the amount of wood being chiselled and has no function to clear the saw dust away. I am not trying to be a know it all here or a pest but I tire myself at work using the proper terminology and getting my guys to learn all of this right so that we have as much consistency between us all from coast to coast continent to continent.

Thanks Phil, yes you are right, ‘raker’ is a slang term for the depth gauge. That is just what we have always called it around here. I will add a note to both articles mentioning this. Thanks for reading!

Good write-up. I didn’t see any discussion about gullet maintenance. Isn’t that part of getting full life from a given chain?

Madsen’s has great articles about gullet maintenance but they are on Square chain square file. What about round file?

Chris, I certainly won’t claim any expertise (see my comment above yours). I looked at the info on Madsen’s and it would seem it should work pretty much the same on round filed chain. Reckon I’ll use that as a starting point for lack of anything else.

This is the first article I’ve read that is actually helpful and spoke a language that was for both easy to read and inclusive so good job thank you I kind of like to know your opinion on chain size I’ve noticed that I have a 72 dl on the Husqvarna 61 that I have. I Recently tuned up a buddy’s of mine who has a 445 with the smaller profile 5/32. I noticed that both saws sharpened by my inexperience technique side by side it just seems like that smaller profile 445 is cutting like butter but then again it just may have been due to the fact that it’s a noticeably lighter saw and just easier on the physical drain of use …but I couldn’t pass up this Husqvarna 61 that was free. I have another bar that is meant for the 5/32 and I was thinking about getting a 80 DL with the smaller profile. I would certainly appreciate your much more experienced input on on your thoughts of the differences of a performance in the different size profile chains. Thank you again for your well Britain and deapth and coherent article.

For the side dominance issue, after sharpening the teeth of one direction, can you switch the saw on the vise not only left to right (handle to tip of the saw) AND UPSIDE DOWN to keep the orientation of the unsharpened teeth in the same orientation? Thanks

I really appreciate your time, expertise and writing /sharing the article. Living in the Midwest there is a constant need to clear limbs and downed trees due to wind and ice, and so I have acquired numerous chainsaws and pole saws over the years living in OK…reading your article definitely cleared up questions I’ve had since a child on how the saw chain works and bonus is it helped improve my saw chain sharpening skills. Much appreciated.

Thank you for taking the time to share this information in such a clear and concise article. Much appreciated!

This is a great summation of how chain works and how to keep it that way. Took me years to get all that too! Now, matching my filing skill to my theoretical understanding- whole different story! Started with oregon filing jigs, then freehand with saw unsecured- as was the fashion for USFS fire crews. Both with mixed but acceptable results, still didn’t really know what was going on after 10 years. Then I started learning how to sharpen chisels, planes, spokeshave, drawknife and kitchen knives, this changed my outlook on chain. Then I became a climber, and I became the chain bitch, so I decided to cheat. I started using a vice, reading glasses and bright side lighting. Clamping the bar allowed me to use both hands to file, but I got tired of tightening and loosening the chain tension every time. Now I put the chain drive links directly in the vice jaws and immobilize the chain for maximal filing enjoyment. After only 20 years of practice, I probably should be better at sharpening, but most of the time my saw is pulling sweet chips and making the other guys jealous. Consistent high performance chain makes tree work much safer and way more fun. Anyways, thanks TreeMugs! Your lessons have and continue to improve my work life.

Great explanation and tutorial. Glad I found this. One question though, I notice on my chain the chisel edge on some cutters are not straight anymore. They start out at the correct angle looking down on them (and I see it much more clearly when the file is in place) some angle and then the angle drops off at the inside of the chisel edge, some also are more jagged. I’m not sure if this just means keep filing or if I have to “dress” the chisel edge somehow to make it even again?

How Are Chainsaw Rakers Measured? (With 3 Brand Examples)

I get it. You want smooth cuts and fewer chips in your wood, and you’re Smart enough to know that eye-balling raker height will never get you clean results. So, how do you measure raker height consistently every time?

A raker guide is the easiest way to measure the depth of your rakers. You can use a vernier caliper, but the guide is faster and more accurate for this particular task. The guide reduces the chances of mistakes and helps make the process quicker.

This article will show you how to measure your rakers with a guide and give examples of different chainsaw brands.

Things To Know Before Working on Your Chainsaw Rakers

The rakers on your saw chain are the teeth that determine how deep the cut will be. That affects how clean the cut is and how often you need to sharpen your chain. If the rakers are too high, the cut will be shallow. If they’re too low, the cut will be too deep.

The idea is to find that happy medium where the rakers barely touch the wood.

You can use a depth gauge or a raker guide to measure the rakers. I prefer the guide because it’s faster and more accurate. They are also cheap and can be found in most parts stores. However, some chain makers will also ship their products with a free guide.

Still, having rakers at the correct height is not enough. You will need a sharp chain to make the clean cuts you need. But that is another topic you can read more about here.

What Is a Raker Gauge?

A raker gauge is a tool that is used to measure the depth of the cutters (teeth) so that you can determine how much wood needs to be removed. There are several raker gauge tools, including a depth gauge, center gauge, and roller gauge, and they all have their own roles.

Let’s take a closer look at these raker gauges and how they can help you with your chainsaw needs.

Center Gauge Tool

The center gauge tool is used to find the center of the cutter. This is important because the chain must be sharpened at the correct angle. If the angle is off, then the chain will not cut properly. These are not as common as depth gauge tools.

Depth Gauge Tool

This is the most common type of raker gauge. It is used to ensure that the cutters have the same depth. The tool is placed over the cutter, and a measurement is taken. If the cutter is too tall, it must be filed down.

Check out the following music video for a demonstration of how to use a depth gauge tool:

Husqvarna has included a depth gauge tool with their chainsaws for many years. But you can also buy it separately.

• Place the chainsaw on a flat surface. A vice is ideal, but you can also use a table or workbench.
• Choose if you want the soft or hardwood setting on the guide. I’ll pick the hardwood side for this example.
• Set the gauge. Place the front notch on the cutter before the one you intend to work on, then make sure the raker you are working on is in the small incision in the hardwood grove.
• File the excess. If the raker is protruding, file it.
• Repeat this process for every raker on the chain. This is a reasonably fast process.

How To Measure the Rakers on a STIHL

STIHL also provides a depth gauge tool with their chainsaws. This one is a little different from Husqvarna’s, with the soft and hardwood on the same side of the gauge, but it works basically the same way.

• Place the chainsaw on a flat surface. A vice is ideal, but you can also use a table or workbench.
• Place the guide over the cutter you want to measure.
• Check to see if the raker is at proper depth by looking at the gauge. If it is protruding, file it down.
• Rinse and repeat for every raker on the chain.

How to Measure the Rakers on an Oregon

Oregon is slightly different from the other two brands we’ve covered. Their depth gauges are not included with the chainsaw. Instead, they are sold separately.

• Place the chainsaw on a flat surface. A vice is ideal, but clumps can work too.
• Select the correct size for your cutter. There are three sizes to choose from.
• Place the guide over the cutter you want to measure.
• Check to see if the raker is at proper depth by looking at the gauge. If it is too tall, file it down.
• Repeat for every raker on the chain.

As you can see, measuring the rakers on a chainsaw is not difficult–regardless of the brand. In fact, the process is very similar, except for a few minor details. After following the steps outlined above, you can ensure that your chain is ready for clean cuts.

Things That Could Go Wrong When Setting the Raker on Your Chainsaw

Overfilling the rakers can cause binding. This is because the depth gauges can no longer measure the cutters correctly. As a result, the chain will not cut as it should. The solution to this problem is to replace the chain.

Underfilling the rakers can also cause issues. This is because the cutters will not be able to reach full depth, which results in a poor cut. The solution is to file the rakers down until they are flush with the cutter.

Another problem that can occur is known as “raker nick.” This happens when the raker is not set at the proper depth and ends up hitting the side of the cutter. This can make the chain come off or, even worse, cause kickback.

Kickback is when the saw kicks back towards the user. This can happen when the raker is not set correctly or the chain is dull. Either way, it can be extremely dangerous and should be avoided at all costs.

The best way to avoid these problems is to regularly check the rakers and make sure the saw is sharp. Doing this can extend your chain’s life and avoid accidents.

I’ve also realized that I need to check my rakers more often than I thought. It’s easy to forget about them when you’re not using the saw regularly. However, it’s important to remember that they play a vital role in the overall performance of your saw.

Final Thoughts

As you can see, setting the rakers on a chainsaw is not difficult. However, it is important to make sure that they are set correctly. Otherwise, you could run into some serious problems.

If you’re not sure how to set the rakers on your saw, I recommend checking out the instructions for your specific model. Or, you could always take it to a professional and have them do it for you.

Either way, make sure that you get it done regularly. It’s the best way to ensure that your saw always performs at its best.

How to Sharpen a Chainsaw

Get (and keep) that chainsaw cutting well by following these steps.

We may earn revenue from the products available on this page and participate in affiliate programs. Learn more

If you’ve run a chainsaw, you’ve experienced it. The same machine that buzzed through firewood or felled a tree with ease suddenly turns into little more than a noisemaker. You can press those teeth against the wood as hard as you want, but progress–if it comes as all–is agonizingly slow. Assuming your blade is still making revolutions on the bar, there’s only one conclusion: Your blade is dull and needs some sharpening TLC.

Lots of things can make a chainsaw dull. Hours spent on hardwood species like oak or hickory simply wear on the teeth and make them lose their edge. But slice through any chunk of firewood and hit dirt or a rock, and your blade can go from sharp to ineffective in a second.

The good news is there’s no secret to sharpening a chainsaw, and the process is not that hard. With the right tools and a little practice, you can turn that butter knife into a cutting machine in just a few minutes. Read along to learn how to sharpen a chainsaw chain, and keep that edge properly maintained.

Clean It Up

The first step in getting a nice edge on your blade is to clean any dirt, grease, or wood residue from the chain. This can usually be accomplished with a soft wire brush or even a rag, while the chain is still on the bar. But if you’ve done some serious tree-felling, your blades might have some serious gunk clogged in the teeth. In this case, your chain would benefit from soaking in a cleaning solution, which requires removing it from the bar. This step also allows you to clean up the bar groove, which can also clog up with debris and affect the saw’s performance.

How to Sharpen a Chainsaw with a File

You must first make sure your chain is properly tightened against the bar if you’re using a file to sharpen it. If your chain is loose or “sloppy” it will move around as you attempt to file and make keeping a consistent angle on the file difficult. For this reason, some sawyers prefer to over-tighten the chain a bit while sharpening to keep it taut, then reset to the proper tension once the job is complete.

Disregard this if you’re using a mechanical sharpener, which may require you to remove the chain from the bar. Follow the instructions below.

Secure the Bar

Keeping the bar clamped in a vise will ensure that the saw won’t move around as you sharpen. You’ll not only have both hands free to work your file and maintain the proper angle for sharpening, and you won’t have to worry about the saw falling off your workbench or other surface. This will not only protect your saw from damage, but it will also keep it from falling against your leg or on your feet.

Get the Tools

Safety: Wear a pair of gloves to protect your hands and fingers from the saw’s sharp teeth, and a set of safety glasses will ensure wood chips, metal filings or other dangerous debris won’t get in your eyes.

File: If you didn’t get a sharpening file when you purchased your saw, manufacturers will recommend the proper size for your unit. These can be purchased at most hardware stores (3/16”, 5/32” and 7/32” are the most common sizes). A surprising number of files don’t come with a handle. You can buy a simple wood handle at the same shop, which will not only make the file easier to grip, but also protect your hands from the pointed end of a metal file.

Guide: While I generally don’t use one, many people like to use a chainsaw sharpening guide. Guides attach to the file and will help you maintain the proper angle as you sharpen and helps make sure you don’t take off too much material or damage the saw’s teeth as you sharpen.

Depth Gauge: This simple tool is laid on the bar after you finish sharpening the saw’s teeth. The depth gauge will ensure that the raker (the protrusion across from each cutting tooth) is not higher than the cutting tooth. If the raker is higher than the cutting tooth it can negatively affect the saw’s performance. If the raker is too high, you’ll need to file it down with a flat file.

Chainsaw Sharpening Angles

If you’re not using a guide, you need to file manually at two angles. First, keep your file at a 90-degree angle (perpendicular) to the top of the bar as you sharpen. Second, guide the file at the angle recommended by the manufacturer. If you’re unsure what that degree looks like, most chainsaw makers etch a mark in the top plate of each tooth that illustrates the proper angle. Hold your file at this angle (while keeping it perpendicular to the top of the bar), and you’ll be hitting the exact angle to get your blade super sharp.

How to Sharpen a Chainsaw with a File

Starting on the right side of the bar, etch the top of a tooth with a magic marker. You’ll use this mark as a reference to let you know when you’ve made a complete revolution of the chain and sharpened every cutting tooth. Holding the file at the recommended angle, make one stroke with the file, directly away from you. Lift the file slightly off the tooth and pull it back toward you, then make another stroke. Remember, files are not crafted to sharpen in both directions, so you’ll only be filing material as you stroke away from you. If you stroke the file both back and forth, you may damage the file. Make 4-5 strokes in one direction and stop.

Using your fingers, move the chain ahead until the next cutting tooth is in front of you. Then file this tooth exactly as you did the one before, using the same number of strokes. Your goal is to maintain (or restore) the C-shape of each tooth with your file. Advance the chain and repeat the process until you’ve made a complete rotation on the bar.

Visually inspect each tooth you’ve filed on this side of the chain. If the number of strokes you’ve taken hasn’t honed it appropriately, file it until you’ve removed enough material to restore the tooth to an appropriate degree. Continue this process for the length of the chain. When you’re satisfied each resembles a C-shape, with a nicely sharpened edge free of debris or corrosion, reverse the position of the saw blade in the vise and copy your actions on the opposite side.

Check the rakers: When you’ve sharpened each cutting tooth on the chain, place the depth gauge on top of the bar, straddling the chain. The depth gauge will have a slot on it that allows you to see the top of the raker. If a raker protrudes above the depth gauge, file it with a flat file until it’s even with the depth gauge. This will optimize saw performance.

Non-Manual Options

While they’re most frequently used by professionals who sharpen a lot of saws, there are a variety of electric sharpeners on the market. They do a fine job, assuming you follow directions provided and make sure you maintain the proper settings for your chain. Also, because you’re not running the sharpener manually, it’s easy to “go at it” a little too long, sharpening your chainsaw. This ends up doing more harm than good. You can cause the metal to overheat and lose its temper, which can make the metal difficult–if not impossible–to correctly sharpen again.

Keeping It Up

The absolute best way to keep your saw blades sharp and running well is to touch them up after every sawing session. It’s far easier to give your chain a quick once-over at the end of an outing than it is to re-work your blades once they’ve been severely nicked or dulled by overuse or debris. So, take a few minutes when you’re done cutting a bunch of firewood, or after you’ve felled a half-dozen trees, to clean debris from your blades and pull out a file and touch them up.

Also, and this is an often-neglected step, inspect the reservoir for bar chain oil frequently and fill it when needed. Like a car running on low oil levels, your saw can overheat without proper lubrication, sometimes resulting in permanent damage. One good habit to establish is to check and replenish chain oil every time you add fuel. Also, don’t neglect other lubrication ports, such as the small one near the tip of the bar.

Knowing how to sharpen (and maintain) your chainsaw will keep it cutting efficiently. Follow these maintenance steps on proper sharpening, and the next time your saw burps to life it will be ready to perform at an optimum level, and you’ll have fun running it.

Trained as a high school English teacher and coach, Scott Bestul left that lucrative field to pursue another—as a full-time freelance writer in 1990. He sold his first story to Field Stream a few years later and has been contributing to the brand ever since.

Tricks of the Trade: Myths and Mistakes of Chainsaw Sharpening

Some sharpening devices combine both the round tooth file and flat depth gauge file. The sharpening tool pictured here also includes guides that make for a more consistent filing job. Photo by Brett R. McLeod

Maintaining a sharp chainsaw chain not only makes for faster cutting, it also reduces wear and tear on the saw and the sawyer. Given those obvious benefits, it still surprises me to see people struggling with dull saws. To compensate for a dull or damaged chain, sawyers often use the felling dogs to create more leverage, or use a comical back-and-forth sawing motion (treating a running chainsaw as if it were a bow saw), which is both unsafe and ineffective.

Here’s a look at some common chainsaw sharpening myths and mistakes:

Using the wrong-size file (specifically for round-tooth chain)

It’s essential to choose a round file that’s the correct size for the pitch of the chain being sharpened. Using the proper size of file allows the filer to adhere to the 80 percent/20 percent rule, by which 80 percent of the file is inside the cutter, and 20 percent is above the cutter, creating a sharp, crescent-shaped hook on the end of the cutter tooth. Using a file that’s too small in diameter will prevent the top edge of the cutter from being sharpened, while a file that’s too large will remove the hook of the tooth, which is essential for efficient cutting. For example, with.325 pitch chain, you should use a 3/16-inch file; for 3/8-inch pitch, use a 5/32-inch file.

Filing the cutters, but not the depth gauge

The depth gauge (rakers) on a chainsaw control how deep the cutter teeth penetrate. Because the top plate of the cutter tooth is angled back slightly, it is essential that the depth gauge be lowered as the cutter teeth are filed back. Failing to file the depth gauge and only filing the cutter teeth will result in smaller and smaller chips with each subsequent sharpening.

Over-filing the depth gauge

Conversely, some people over-file the depth gauge so that the saw takes a bigger chip. The result is that the saw is overworked and bogs down; it also makes the saw prone to kickback.

Using a dull file

Chainsaw chain is extremely hard and requires a sharp file. As you push and add pressure to the file you should feel it grab. If adding pressure causes the file to skate, chances are your file is worn out. If you’re using a filing tool where the file is in a fixed position, remember to regularly rotate the file for even wear.

Not bracing the saw properly

The best way to brace the chainsaw when sharpening is to place the bar in a bench vice. Keep even pressure with each stroke, and keep the number of strokes consistent for each tooth. If sharpening in the field, consider using a stump vice, or brace the tip of the bar on a log and lock the chain brake.

Filing backwards

Always file from the inside of the tooth to the outside, and don’t drag your file backwards. Filing from the outside to the inside will wear out the file in short order since the outside of the tooth is chrome-plated and harder than the file material. You’ll also find it easier to line up the file guide and maintain a more consistent stroke when working from the inside of the tooth.

by Brett R. McLeod

Brett R. McLeod is an associate professor of forestry and natural resources at Paul Smith’s College and the author of The Woodland Homestead: How to Make Your Land Productive and Live Self-Sufficiently in the Woods (Storey Publishing, 2015).

© 2018 by the author; this article may not be copied or reproduced without the author’s consent.

Discussion

Thanks Brett, for sharing such a nice information. Believe me almost everyone that are using chainsaw have same type of myths.

I think Over-filing the depth gauge point you have explained just for me:)

I will surely share this unique guide with my friends and family.

Thanks again

Hi Brett I agree with you that for proper and perfect sharpening of chainsaw it’s mandatory to use the correct size file. How could identify a dull file?

To ensure a respectful dialogue, please refrain from posting content that is unlawful, harassing, discriminatory, libelous, obscene, or inflammatory. Northern Woodlands assumes no responsibility or liability arising from forum postings and reserves the right to edit all postings. Thanks for joining the discussion.