Circular saws are one of the most important tools for carpenters and woodworkers, as their efficiency and precision ensure that you can make quick straight or curvilinear cuts on wood over and over again without tiring.
But a saw is nothing without a blade. A sharp circular saw blade is crucial to achieving smooth and quality cuts. However, as you use the saw, the blade wears down and becomes dull.
You’re probably already aware that dull blades are not only ineffective but also quite dangerous. What you might not know is that you don’t immediately need to replace them because you can sharpen them yourself!
To sharpen a circular saw blade you only need a file, clamp, and marker. All you have to do is remove the blade from the tool, secure it, mark the starting place, file the blade, and trim the tips.
While this might sound rather straightforward, it’s actually a complex process that requires precision and patience. If you want to learn how to sharpen a circular saw blade the right way, take a look at the step-by-step guide and the tips in this article.
Should I Sharpen My Circular Saw Blades or Replace Them?
You’re probably wondering about the benefits of sharpening your circular saw blade as opposed to simply buying a replacement. Well, to start with, circular saw blades are expensive!
If you’re using your saw daily, you’re going to wear down your blades quickly. Constantly replacing them will have quite a heavy impact on your wallet. Sharpening the blade will leave it as good as new and extend its life.
However, there’s something you should know first. Sharpening circular saw blades is a professional skill that requires practice and quite a bit of patience. What’s more, some blades like carbide-tipped blades should only be sharpened by an expert. Otherwise, there’s a high risk of permanently damaging or ruining your blades.
Even if you get your blades professionally sharpened, the final cost will still be less than what you’d have to spend to replace them, so don’t dismiss this idea yet.
How Do I Know If My Circular Saw Blade Needs Sharpening?
There are several signs you’ll notice when working with a circular saw that can let you know when your blade needs sharpening.
The main one is a decrease in the quality of your cuts. If your blade starts making rough cuts, then it’s time to sharpen it. The change in quality can be seen by inspecting the sawn edge and noticing that the material is chipping or shows an increase in black soot and burrs.
Moreover, if you feel you have to apply considerable effort to move the saw along the workpiece as if you were pushing it forward, then, your blade might be dull.
If smoke arises, or you smell burning wood during the operation of your circular saw, it can be an indication that your blade has to be sharpened.
Another sign of having a dull blade is the sound of the motor. Pay attention to how the motor sounds when the blade is in good condition, and if you notice a change in this sound, it means that the saw is working harder.
Sharp blades require less horsepower, so the tool works silently. Dull blades, on the other hand, overwork the motor and can decrease the life of the saw.
Dull blades also make the tool more prone to kickback, so pay attention to how your circular saw behaves and, if necessary, either sharpen or replace the blade to prevent any accidents.
Step-by-Step Guide on How to Sharpen Circular Saw Blades
Now that you know how to recognize a dull blade, it’s time to learn how to sharpen a circular saw blade. There are two options when it comes to sharpening a circular saw blade, using a Dremel tool or doing it by hand.
In this article, we’ll teach you how to sharpen a dull circular saw blade manually. For this, you’ll need a file, clamp, and marker or masking tape. Then, you should follow the step-by-step instructions down below.
1. Prepare the Blade
Before you begin the actual sharpening process, you need to prepare the blade. You obviously can’t sharpen it while it’s attached to the circular saw because you risk cutting yourself and getting inconsistent sharpening results, so you’ll have to remove it.
Removing a circular saw blade is very easy since most saws feature a blade release switch. If you have an older model, you might need to use a wrench to loosen the bolts.
Next is securing the blade by fixing it to your workstation, so it doesn’t move while you sharpen it. The best way to do this is by using a vice grip. Clamp the blade so it’s facing upwards and the teeth are pointing towards you.
Be careful not to tighten the vice too much because you can bend the blade.
Lastly, grab a marker or some tape and make a mark on the first tooth you intend to sharpen for reference. This way you’re going to know when you have sharpened all the area around the blade, and avoid double sharpening.
2. File the Teeth
Once your circular saw blade is secured and ready to be sharpened, the fun part—filing— begins!
As the blade is used, the tips are worn down, leaving them uneven. So the very first step is filing them to ensure that they’re all the same size. Now you can sharpen the teeth by following these steps:
- Take your file and hold it flush against the tooth at a 20° angle with regard to the bevel.
- Run the file in four smooth strokes along the bevel.
- Move on to the next tooth, and repeat the process, making sure to apply the same amount of pressure.
- Once you’ve sharpened all the teeth, release the circular saw blade from the vice clamp and turn it over. Repeat the sharpening and filing process on this side.
Even though these four steps might look simple at a first glance, the whole process requires a lot of patience and time. The key to sharpening a circular saw blade and keeping it in a usable condition lies in always holding the same angle, using the same amount of strokes, and applying even pressure on all the teeth.
3. Trim the Tips
The last step is to trim the tips again to get rid of any burrs the sharpening process might have left and ensure all the teeth are even. Don’t worry, this is probably the easiest part of sharpening a circular saw blade. You don’t even have to apply many strokes. Simply run the file back and forth a couple of times on each tip.
4. Install the Blade
And that’s it! You’ve sharpened your circular saw blade, and all that’s left is to attach it to the saw again.
Remove the blade from the vice grip, clean it and brush away any filings. Then, you can reattach it to your saw and enjoy it again.
How often should I sharpen a circular saw blade?
There’s no clear-cut answer to this question. A good quality blade can typically be sharpened between three to four times, but it’ll depend on how worn and damaged the teeth are. If you use your blade for heavy-duty or intensive tasks, then there’s a high chance that the teeth will end up highly damaged and worn, so there won’t be enough material to sharpen it.
If you’re not sure whether you can sharpen your circular saw blade, then you should consider contacting an expert who can check your blade and give you an accurate answer.
Circular Saw Blade Caring Tips
Sharpening your circular saw blade is not the only way to extend the blade. There are some other maintenance tips you can keep in mind to care for your blade in the right way.
Keep the Blade in a Dry Area
Proper storage conditions for when the blade is not in use is one of the most important aspects of blade caring. Moisture and humidity can cause corrosion, which, as you probably know, can be deadly for metal blades and for the circular saw itself. Once you’ve finished using your saw, remove the blade and store it in a dry place.
Hang the Blade from the Center Hole
While we’re on the topic of proper storage, you should hang the blade from the center hole when you’re not using it. If the teeth are in contact with the floor or a shelf, they might get dulled from brushing against these surfaces, and gather dirt and dust more easily.
Regularly Clean the Blade
Even if you store your blades the right way, they’ll still accumulate dust and grime that can hinder their performance and cutting ability significantly. To keep them working properly, clean your blades frequently using a nylon brush and a solvent. Simply soak them in the cleaning agent for approximately 20 minutes and then brush them.
The agent you choose should be gentle, so it doesn’t remove any protective coating the blade might have.
Cool the Blade
If you’re going to be cutting for long periods, it’s important that you plan for a few breaks in between your project. Blades can get hot, especially if they’re low-quality, so you should allow them to cool down before getting back to work.
Use the Blade for the Right Task
This should go without saying, but there’s no better way to blunt your circular saw blades than by using them for the wrong task. There are different types of blades that are designed for specific materials. Not using the right blade for the job at hand will not only blunt it quicker, but it might also damage it and your workpiece.
If you don’t want to compromise the quality of cuts you can make with your circular saw, then you need to use a sharp blade. When you find yourself replacing your blades too often for your liking, you might want to consider learning how to sharpen them yourself.
Granted, learning how to sharpen a circular saw blade is no easy task, but you can acquire the proper technique by practicing on older blades and avoid damaging newer ones.
If you follow our step-by-step guide and our care tips, you can extend the life of your blades so you don’t have to replace them that frequently.