How To Sharpen A Circular Saw Blade

There is a need for you to know how to sharpen a circular saw blade. After all, it is not proper to let the blades get dull after several times of use. Among all the parts of the saw, the blade is the one that needs a lot of caring. If you really want to extend the lifespan of this tool, then sharpening its blade is highly necessary.

You will know that your blade is already dull if it is having a hard time in cutting. You should know this by yourself. Specifically, the difference between a sharp and brittle blade is too apparent.

Many users would just tend to buy a new blade if in their current one gets dull already. However, we do not advise you to do that. Using these tools should be cost-efficient. If it can be repaired, you should repair it. Avoid unnecessary expenditures. Or else, you won’t really see the value of your power tools.

With the right tools, you can sharpen the blade of a circular by yourself. Here are the proper steps to do it.

How To Sharpen A Circular Saw Blade

Materials you need

  • Marker or Chalk (Should be washable)
  • A Bench Vise
  • Handled File Set (Three pieces preferably)
  • A strip of wood (300 mm long; 8 mm thickness)
  • Socket set (Heavy duty)
  • Painters brush (25mm + preferably)
  • Wire brush (You will need a lot of this)
  • Jig

Cleaning materials

  • A pair of gloves
  • Rags (for cleaning the area and the blade)
  • G clamps
  • Petroleum jelly

Initial Preparations

  1. Before starting, you should secure your safety first. Making sure that the circular saw has no power is important. You don’t want the motor to run while you are disconnecting the blade. It can pose potential harm to your hands.
  2. Take the thin strip of wood and clamp it between the saw bed and the tooth. Doing this prevents the blade from accidentally spinning while you are removing the bolt that holds it.
  3. You will also the help of a jig in the sharpening process. A jig is a 300mm baton that has a short piece of wood attached to its end. A coach bolt, washer, and wing nut will also help in attaching the blade to the stick. With all of these present, you can keep your blade steady while you are sharpening it. Just flick the wing nut if you want to rotate the blade to sharpen its next tooth.
  4. Take your soft brush and dip it to your petroleum jelly. Brush the entire body of the blade and let the compound sit there for around 30 minutes. Doing this aids in breaking the resins in the teeth of the blade.
  5. After 30 minutes, start clamping the blade in the jig. Next, use a WD40 cleaner and wire brush to clean the blade. When you are brushing, you should begin from the inside then out. Specifically, the cleaning motion should be like of a CD. Soak a rag and rub it against the blade so that you can remove the residues and other fine powders. Moreover, you should not be scared brushing the teeth portion!

Sharpening Process

  1. You need to use your chalk and mark the upper portion of the blade. In this way, you will know if you have already finish sharpening the entire disc. Double sharpening is not a good idea, by the way. Aside from the fact that it can take your time, it can also harm the quality of the blade.At this point, you will notice that between two teeth, there is a bevel that is facing towards you. Take your file and clutch it at a 20-degree angle (based on the bevel). Afterward, give the bevel of the first points four simultaneous strokes. Use a consistent up and down motion to do this. You can quickly notice if you did it successfully. If not, just do more stroke again.
  2. Always pay attention to the bevel. Specifically, you should skip one point and just go to the succeeding beveled edge instead. You should do this because the bevel is present on every other tooth. Just continue doing this process until you can go around through the entire blade disc. Moreover, the strokes should be equal with the first one.
  3. Once you complete a single rotation, do the same process once again. This time, you will still need the help of the mark to know where you have started.
  4. After this, you will need to start filling the blade. Specifically, you have to file each of the tips of the teeth. At this point, you are only required to run the file back and forth, instead of applying multiple strokes. Always aim the front edge that you can see on the blade point. Obviously, you have to do this on all of the teeth of the blade.
  5. When you are done, you can already clean the saw blade using a clean rag. Remove all the residues and other remaining debris. Your blade should be good as new now!


Knowing how to sharpen a circular saw blade is essential knowledge for the owners of this tool. Even the professionals in the industry would recommend learning this skill. After all, nobody wants to waste money on constantly buying blades when the current one gets dull. Of course, it is not economical, and it doesn’t relish the DIY spirit in you!

However, sharpening your blade from time to time will eventually lessen the integrity of the teeth. Specifically, the teeth will grow smaller because of constantly shedding new layers. Therefore, in your next sharpening, make sure that you will do deeper gullets that the previous one. If you don’t do this, the shape of the blade will look distorted. When this happens, you have no choice but to buy a new one again.

In sharpening, always be careful with the blade. Even if it is dull, it has still the capacity to wound you. As a piece of advice, wear a pair of gloves for a foolproof work process!