How To Sharpen a Circular Saw Blade

Sharpen the dulled circular saw blade on grinder machine.

Quite frankly, if you would ask me whether you could sharpen your circular saw blade or not, I would answer with alacrity that you could. But it depends on what type of circular saw blade you have. If you are using something that costs more than $50, I bet you can sharpen and reuse such a saw blade. But if you are using a cheap saw blade, I would advise you instead to dispose of it or repurpose such a blade.

As you engage in many woodworking tasks using your circular saw, you will soon find yourself replacing blades more often rather than sharpening them. The reason is that sharpening the dull saw blades takes time and effort. Hence, many would instead buy a new one if money isn’t an issue for them. But it will also help if you know how to sharpen your dull saw blades, for you can save money if you do.

Steps on How to Sharpen Your Dull Circular Saw Blades

Before you can sharpen your saw blade, you need to know if it is dull. Dull blades usually leave burn marks on the stock. They also cause binding. Moreover, there is an increased tear out and chipping when you make cuts with a dull blade. Besides, the circular saw motor is becoming noisier than usual. Of course, these tell-tale signs indicate the dullness of the blade, and if you see these signs, you can sharpen your blade. Here is a rundown of the straightforward steps on how to sharpen your circular saw blade:

Step 1: Detach the Saw Blade from Your Circular Saw.

The very first thing to do is turn off your circular saw. Detach it from the electrical outlet. Afterward, you can start detaching the blade. Check the manual on how to disconnect the saw blade. Your circular saw usually comes with a blade release switch to allow you to remove the saw blade effortlessly. Once you’ve clicked on this switch and have removed the saw blade, you can stack away your circular saw to a secure place. When sharpening, you want to clear your workspace.

Step 2: Secure the Blade Using a Vise-Grip

You can use a vise grip to secure the blade while you sharpen it. The saw blade’s teeth should point toward you, and the blade should be facing upward. Don’t tighten your grip on the blade too much because it may cause warping of the blade’s metal that holds the teeth.

Step 3: Start Making Marks

Mark the blade’s top side. In this way, you will not get confused as to whether you’ve got the whole circumference of your saw blade covered. This mark will also help you avoid double sharpening. You can mark a tooth of the blade using a grease pencil. From there, you can start sharpening the saw blade. Using your vise, clamp the saw blade with the tooth that you’ve marked vertically extending. Ensure that you clamp the blade’s body and not the teeth of the blade. 

You will notice that with each two-blade point, you’ll find a side bevel that faces you. Make sure you familiarize yourself with the angles of the blade. So, it will be best to use a file and hold the saw blade at a 20° angle relative to the bevel.

Step 4: File the Teeth of the Saw Blade Using Sharpeners

Using up and down strokes, you can pass the file four times near the first tip bevel. If you feel that you need to add more strokes, you can do so until you get satisfied with the sharpness. File the back tooth’s face several times utilizing horizontal stroke. Then, position the file on the next tooth. 

Skip one tooth, for saw teeth alternatingly tilt to different directions (left and right). So, you need to skip one tooth to file those teeth that have similar tilting directions. Once done filing teeth with the same tilt, you can start filing the teeth in the opposite direction. You can do this by turning the blade over.

Step 5: File the Tips

You should file the tips of each tooth. You don’t need to overdo it. You only need to run your file to and fro so as not to wear it down. If you overdo the filing, you may end up with a less pointed blade. You can do the filing for the blade’s tips. In this way, you can ensure that the tips of the teeth are also sharp.

Step 6: Re-attaching the Blade

Once you are sure that you have sharpened well the saw blade’s teeth, you can then re-attach the blade to the circular saw. Unclamp the saw blade from your vise clip. Once you’ve loosened it, you can then attach it to the circular saw. Ensure that the blade is clean before attaching by brushing away the fillings.


Sharpening Tips for Your Circular Saw Blade

Aside from knowing the simple steps on how to sharpen circular saw blade, it will also help if you are cognizant of the following valuable tips when sharpening circular saw blades:

You Can Practice Using Broken Blades to Avoid Damaging the Good Ones

As a beginner, you will be in for a rough ride using the circular saw. Until you become confident enough to use the circular saw, it will help to use broken blades for practice cutting. Saw blades are not inexpensive. So, if you use the good ones for practice, you may end up damaging them, which can pad up your expenses. So, it will help if you practice using saw blades with some broken teeth. You can also use them for practice sharpening.

Clean Your Saw Blades Regularly

Grime and dirt may accumulate on your saw blade over time. It will indeed affect the blade’s cutting performance. Moreover, you may think that the saw blade is dull because of this dirt and grime accumulation. When cleaning grime and dirt, however, you should refrain from using strong chemicals. Such chemicals can strip the blade of its protective coating. 

You can use, for example, a nylon brush to do away with this dirt and grime. You can also complement this nylon brush with a solvent or any cleaning agent. You can soak the blade onto the cleaning agent for twenty minutes. Afterward, you will see that the grime and dirt will dissolve in the solvent, leaving the saw blade clean again. Without grime and dirt, you can quickly see if the saw blade needs sharpening.


Frequently Asked Questions

Aside from knowing the abovementioned steps and tips on sharpening dull blades, you can also familiarize yourself with the following frequently asked questions about saw blade sharpening:

How Will I Know If the Carbide-tipped Blade is Already Dull?

There are tell-tale signs indicative of the fact that your carbide-tipped blade is already dull. Such indicators include noisier overworked motor, inferior cut quality, excessive chipping of material, and burn marks becoming more frequent

The first tell-tale sign, of course, is when your circular saw motor is exhibiting more noise. This sign means that its motor is overworked because the blade does not cut well. Thus, the saw motor needs to work double-time. 

Another indicator is inferior cut quality. Well, this is pretty obvious if your saw blade is no longer sharp. It will produce imperfect cuts that would indeed frustrate you. 

Third, you will see excessive chipping on the edges of the cuts. Such chipping will happen if the blade is dull and the teeth could not cut smoothly and swiftly through the material. 

Lastly, you will see burns along the cut because the saw blade is overheating more often. This indicator means that instead of cutting smoothly, the saw blade causes more friction when plowing through the material. The abovementioned tell-tale signs, of course, are sure indications that your blade is getting dull.

How Much Would It Cost to Have Your Saw Blades Sharpened?

Well, it all depends on what option you would take. Of course, you got two options when it comes to sharpening your dull saw blades. First, you can have it serviced by a professional whose job is to provide service for blade sharpening. The service fee will depend on the charging fee of the professional. On the other hand, you can sharpen your dull blades on your own.

You will pay somewhere between 25 cents to 50 cents for each tooth of the blade. You’ll end up, however, with a circular saw that is somewhat brand new. Nevertheless, it will cost you more if your blade is carbide-tipped because it necessitates the use of specialized tools. On the other hand, if you got a cheap saw blade, don’t bother to have it sharpened.

Would It be Easier to Do the Sharpening of the Saw Blade on Your Own?

If you got the time to spare for the sharpening of an old saw blade, I think it will be easier. Yet, sharpening a dull saw blade takes time and effort. It isn’t a job for the impatient. Thus, if you got the money to spare for sharpening your old and dull blades, you might as well go for the service of a professional. Remember that to sharpen saw blades with carbide tips, you need a dedicated tool, something with diamond wheels. You will also need a cutter grinder for this purpose. The cutter grinder, of course, is the best tool for sharpening dull saw blades.

Can You Sharpen Dull Blades More Often?

You can sharpen good quality saw blades at least 3 to 4 times, depending on how damaged and worn the blade’s teeth are. If the saw blade has teeth that are highly worn, you may not be able to sharpen it because there might not be enough material in the blade to file.

How Long Would a Newly Sharpened Blade Last Before It Needs Another Sharpening?

Well, it depends on the blade type and how you use the blade. Most quality blades can last a maximum of 120 hours of use. But if you use them in heavy workloads, they can last only for several hours. So, the answer to this question depends on the blade type and how you use the blade.


Conclusion

Sharpening dull saw blades requires great patience. If you don’t like monotonous jobs, you may also not like sharpening dull saw blades. The reason for this is because it requires time and effort. As mentioned above, you need to file each tooth individually. Then, you need to flip the blade over to file those teeth that tilt in the other directions. Such a tedious task may snuff your patience out.

Nevertheless, as a woodworker, you may not always have the benefit of having an extra blade at hand. Moreover, you may find it hard to find a professional to sharpen dull blades for you. Plus, you may not have the money to buy more saw blades. In such a case, it will indeed help if you know how to sharpen dull saw blades.

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