How to Sharpen Circular Saw Blades

Circular saws are precious tools in a woodworker’s kit. They enable you to make a range of straight cuts easily and quickly. However, any circular saw’s performance depends on what blade you put in it, and with a blunt blade, your saw will be unable to make accurate, clean cuts.

While it’s very easy to replace a blunt blade simply, you can save some cash for yourself by sharpening your blade. It’s not that hard, will greatly extend the life of your blades, and doesn’t take too long. If that interests you, here’s a guide on how to do it.

Different Types of Blades

Of course, before you can sharpen your circular saw blade, you have to know which type of blades you have. To be specific, you need to know how the teeth of the blade are arranged. For instance, cross-cutting blades teeth are aligned in an alternate top bevel pattern while ripping blades have teeth aligned all in the same way.

You will also need to know the material that your blade is made of. High-speed steel usually makes up most of the less expensive blades. High-speed steel blades can be sharpened using a regular file

On the other hand, sharpening a carbide-tipped blade is a little more complicated. This blade is designed to be extremely durable and hard, so a regular file won’t be able to get the job done. What it requires is a diamond file. However, a carbide-tipped blade owner might prefer to take it a professional to sharpen it.

1. Sharpening a Regular Ripping Blade

What you will need to sharpen your regular ripping blade is: a marker pen, a file, and a bench vice

It doesn’t matter what type of circular saw you have –a worm drive saw, a sidewinder, or even a mini circular saw, make sure that you saw is turned off and is not connected to any power source before removing the blade.

After you remove the blade, you take it and fasten it to the bench vice. If you clamp the blade too tightly, you might risk damaging the blade, so take care of that. Your blade will be worthless if you bend it since it will no longer be able to cut in a straight line.

After you have fixed the blade in the vice, take your marker pen, and on the first tooth, you are going to sharpen put a mark. Doing so will allow you to know when you have made a loop and sharpened all your blade’s teeth, and will help you avoid double sharpening them.

Then, take the file and begin sharpening the first tooth. The advised technique is to file in one direction and going only with a forward motion. Because if you file forward and backward, your file will be worn out much faster, and you won’t be able to use it anymore.

You will begin to see clean steel on the blade after a few strokes. This means that now the teeth should be sharp and you can move to the next one.

Instead of loosening the vice and rotating the blade for every single tooth on the blade, you may be able to sharpen three or four of the teeth before you need to rotate the blade.

Continue around the blade all the way until you come to that tooth that you marked with your pen in the beginning. When you see the market tooth, you know that now your blade is sharpened and is ready to go. Now you only need to remove it from the vise and put it back in your saw to start using your freshly sharpened blade.

2. Sharpening a Crosscutting Blade

The key difference between a crosscutting blade and a ripping blade is that cross-cutting blades usually have their teeth with alternating bevel angles. This means that –unlike ripping blades- cross-cutting blades require to be sharpened in alternating directions.

Sharpening a crosscutting blade is just as easy as sharpening a ripping blade. All you need to do is follow the exact same basic steps, fastening the blade in the vice, and then marking the first tooth with a marker pen. The difference here is that when you sharpen the teeth, you need to sharpen every second tooth.

After you have gone all the way around your blade, you need to remove your blade from the vice, and then put it back in the reverse direction to sharpen the other set of teeth in the opposite direction.

After you finish sharpening the second set of the blade’s teeth, you can remove the blade, insert it back in your saw and get to use it.

Can You Use an Automatic Sharpener?

You also can put an automatic sharpener to use to help you sharpen your circular saw blades. This much faster technique is a little bit hard on the edges and probably won’t be able to give you such as good a result, however.

Automatic sharpeners can overheat as well, and sometimes they might lose the correct angle while you are working.

While, of course, using a hand file to sharpen your circular saw blade manually might be a little more time consuming, it usually gives you a better result. Even more, some people actually enjoy the activity of sharpening their blades manually; they find it relaxing and meditative even.

How to Know if Your Blade Needs Sharpening

So, you may be wondering how you can tell when your circular saw blade needs to be sharpened. Well, the simple way to tell is if your blade is struggling to cut through a piece of wood that it normally has no issues with.

Also, make sure that the blade is the correct type for the wood or any other material you are going to cut, and if it still gives you a hard time, it might be a good indication that it’s time for you to get the file and vice bench.

If you neglect to sharpen you blunt blade, it will give you cuts with some rough finishes. The saw motor would have to work harder, eventually causing it to burn out faster, and will have an increased risk of “biting” as well, making the work more dangerous

However, you can still use a dull blade. Dull blades are fine for making very rough cuts, cutting wood that might have nails in or for demolition work.

Sharpen Your Blades to Extend Their Lives and Save Some Money

In the end, sharpening your blades yourself won’t take too much time and is a great way to extend the saw blade’s lifespan, while also saving you a bit of cash. Doing so is not difficult and doesn’t need any special equipment, so anyone can do it themselves at home. And some people even say that is has a recreational value in it. So maybe it’s time to consider sharpening your own blades and have some fun with it.

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