To many, a chainsaw might seem like an invincible tool designed to cut wood and other materials without a second thought. While it is true that a chainsaw is powerful, it is not invincible, and as with any tool which comes into contact with others, its blade will need to be sharpened eventually.
If you use a chainsaw and have never had to or thought to sharpen your chainsaw’s blade, then it may be time you did so. To help you, we are going to explain when to sharpen, what you’ll need, the safety precautions you must follow, and outline more than one way that you can do so.
When to Sharpen
Thankfully, there are couple of clear pointers that it may be time to sharpen your chainsaw blade. The first might seem obvious but it still needs saying, and that is when the chain becomes dull.
A chain saw should cut with the minimum of pressure, and it will if the blade is sharp, so if you feel that you are having to apply ever-increasing force in order for it to cut through materials, it probably needs sharpening.
Another clue is actually a visual one in relation to what waste material is created when you are using your chainsaw to cut through wood. A sharp blade will create chips when it is sharp, but it will be sawdust it creates when it is dull, so when you are seeing more sawdust than chips, it’s a sure sign that it’s time to sharpen the blade.
Different Ways to Sharpen Your Chainsaw Blade
There are many jobs related to DIY, tools, and maintenance where you have no choice, and must follow the designated way to do it, but thankfully that is not the case with chainsaw blade sharpening.
There are several ways it can be done, but we are going to mainly focus on how to do it by hand. The reason is that this tends to be the most effective especially as you can see the cutting edges of the blade close up. However, there are power options which we will briefly outline.
File Sharpening By Hand
Your first thought might be that sharpening a chainsaw blade by hand is going to a long and tedious process, but it need not be. The benefit of doing it by hand is that you can be more accurate and precise. Here are the steps to follow:
1. Select the correct file types and sizes of the files you will need based on the size of the semi-circular cutting edges around the blade. These sizes are likely to be 5/32, 3/16 and 7/32 inch. Most DIY stores will sell chain saw sharpening files as a set so that you have all the sizes necessary. You may also want to purchase a sharpening guide that can be used in conjunction with the files.
To ascertain which files are right for your chain saw, look for a code digit etched on the blade which you can then use to identify its chain pitch and the file required from the table below.
CODE DIGIT |
CHAIN PITCH |
ROUND FILE SIZE REQUIRED |
1 |
1/4″ |
4.0mm |
2 |
.325″ |
4.8mm |
3 |
3/8″ |
5.2mm |
4 |
.404″ |
5.5mm |
6 |
3/8″ Picco |
4.0mm |
7 |
1/4″ Picco |
3.2mm |
Incidentally, ‘Picco’ refers to chain saw blades on those chain saws manufactured by Stihl. Stihl is the world’s biggest chain saw manufacturing company, so much so that they even make their own chain saw guide bars and saw chains.
2. Ensure you have all the necessary safety equipment which includes gloves and safety goggles. Even if a chain saw blade is regarded as dull, it is still extremely sharp, so be aware that it can still cause you a nasty cut.
3. To get started, secure the chainsaw, preferably in a vice so that when you start sharpening, it cannot move. You should also engage the brake. Both of these actions are extremely important with regard to your personal safety, so double-check them.
4. Using the appropriate file size as based on the diameter of the cutting edge, file every second blade by holding the rounded file at right angles to the chain. Your filing motion should be forwards and as smooth as possible. If your chain saw blade has been made by Stihl, the angle of the file should be 30° instead of 90°.
(Note that a useful tip to locate which specific blade you started with is to mark it with a permanent marker before you begin.)
5. To progress, unlock the brake, move the chain as needed and then lock the brake again. Continue sharpening each alternate blade. Once you have completed one side, loosen the vice, and turn the chainsaw around and then secure it again. You can now proceed to sharpen the other side of the chain.
6. You should also sharpen the depth gauges which are between each blade. This should be done using a flat file instead of the round one you used for the blades. Follow the same process with regards to sharpening alternate ones and reversing the chain saw as you did when sharpening the blades.
7. As a guide as to whether you have correctly sharpened each cutting edge, you should check to see whether it is dull or bright. A dull cutting edge means it still needs sharpening; a bright cutting edge means it has been properly sharpened.
Power Sharpeners
There are basically two types of power tools for sharpening a chain saw blade and these are bench sharpeners and handheld sharpeners.
A bench sharpener is one that is clamped to a workbench, and the sharpening method requires the saw chain to be removed from the saw. It is then clamped to the sharpener, which is then powered on and sharpens a specific blade.
To progress, the saw chain is released, moved so the next alternate blade is in position, and then clamped again. This continues until every blade in the saw chain has been sharpened.
Handheld sharpeners follow much the same process as sharpening by hand but instead of using a file to sharpen each saw chain blade, you use the power sharpener.
Handheld sharpeners are similar to rotary grinders, and while they can sharpen very quickly, care must be taken, not just for safety reasons, but to ensure you do not damage any blades or depth guides.