How to Sharpen a Circular Saw Blade: A Step-by-Step Guide

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Circular blades are a powerful tool that requires maintenance and sharpening at regular intervals. But learning how to sharpen a circular saw blade can seem arduous due to the steps you have to follow.

Not to worry, because there are easy ways to sharpen circular saw blades. Our woodworkers will show you the steps and materials to save you both the cost and hassle.

Sharpening Your Circular Saw Blade in 8 Steps

Tools and Materials You'll Need

Step #1: Dismantle the Blade

The first step to sharpen a circular saw is to remove and disassemble the blades. Removing the blades allow you to clean them blade easily. 

milwaukee m18 circular saw

To remove the blade from the saw, use a ring spanner and turn the knot in a clockwise direction. Gently remove the circular saw blade from the circular saw. 

Step #2: Prepare the Blade for Sharpening

Whether you want a carbide-tipped circular saw blade or a regular one, fixing the blade into a workbench is necessary. Make sure it is clamped properly and will hold its place. 

Use a two-screw clamp to prepare the blade for sharpening. The blade should clasp strong so that it doesn’t move much when you start to sharpen. Vibrations are common when you refine a circular saw blade, but keep it minimal as much as possible.

Step #3: Mark the Blade

To identify which part of the circular saw blade has been sharpened, it’s a must to put markings on the dull blade. This step is your clue to knowing when you have sharpened a full cycle already. 

marking circular saw blade

Glue sandpaper on the wood and lubricate it with oil. Sand, the face of the circular saw blade, starts filing back and forth. Tilt around 20 and file up to 4 times along the slope to file the blade correctly.

Step #4: Trim the Teeth

Trimming is necessary to even out the row of blade teeth as this dulls over time. Use the flat file to file the teeth until it’s all at the same height. Repeat the horizontal filing over one tooth and repeat on the other rows of teeth. 

Step #5: Set the Teeth

To avoid the circular saw blade from getting caught in the workpiece, ensure that it has mutually bent teeth. This allows the saw cut to be wider than the blade and prevents the wood or preferred material from getting stuck in the saw when cutting wood. Use pliers in conducting this step to ensure that the set is evenly directed on both sides.

When you refine a circular saw blade, be cautious in bending the tooth, and file it accordingly to where it is directed and planned, or else the teeth might break, making the saw unusable.

Step #6: Start Sharpening the Blade

After filing the teeth, you can now sharpen a circular saw blade. Grab a triangular file three to four times over each tooth until you achieve a uniformly pointed shape on all sides of the saw blade. 

sharpening a circular saw blade

The teeth should look identical after sharpening. Gradually file to avoid adjusting each tooth and prevent the tips from being uneven.

You can also opt for a crank sharpener or a diamond file when sharpening a circular saw blade with carbide tips. Set your sharpening stick flat on the wood, and ensure it fits into the gullet. 

Sharpening sticks wear quickly, so we recommend buying them in packs to save costs and trips to the grinding shop.

Step #7: Place it Back on the Saw

Re-install the sharp blade to the circular saw and ensure it has a correct and aligned fit. When using a ring spanner, it should be tightened by turning the bolts in a left direction. 

Check if all the teeth have been filed evenly, as sharpening requires even filing. To do so, track a standard filing number and do it one at a time instead of filing multiple times immediately.

newly sharpened circular saw blade

As you learn how to sharpen a circular saw blade, you will notice that there are different blade heights, and the goal is to even it all out, whether it be a carbide blade cut or the common circular saw blade.

Step #8: Test it Out

Conduct a snap check to confirm that the circular saw blade will work properly when used for cutting wood. Try on a small wooden block first, and check whether the cuts are making even bites. 

The most common indicator that the saw blade was sharpened correctly is that the saw doesn’t produce excessive noise when operating. A sharp blade will make it easier to cut. If you notice otherwise, there’s a huge chance that the blades are not sharpened evenly, causing uneven cutting. 

Indicate surface markings and use them as a comparison of the segment heights. Reduce carefully until all teeth are of the same length. 

Additional Tips + How to Work With a File

sharpening circular saw blade with a file

Sharpening a Circular Saw Blade Using a Dremel

Dremel multi-function grinders are built purposefully with different attachments so they can be used as blade sharpeners. While a dull blade can be sharpened with a Dremel, you may have a hard time maintaining the angle. 

To sharpen circular blades with a Dremel, having a steady hand is a requisite. However, if you’re not gifted with such skill, you should secure suitable tools and devices for clamping. Blade sharpeners don’t work independently, and manual knowledge is still necessary. 

sharpening circular saw blade with dremel

Dremels have a suitable attachment for sharpening a toothed blade, which simplifies the process, eliminating the arduous job of filing and sharpening. 

Should I Sharpen the Blades Myself or by a Professional?

Sharpening circular saw blades by yourself, or a professional has pros and cons. If you’re a woodworking professional with an array of saws that need to be sharpened regularly, then getting your blade sharpener is a reasonable investment.

With DIY blade sharpening, you also need the right tools, or you’ll repeatedly re-sharpen your circular saw blade, ending up with damaged blades. 

Sharpening circular saw blades on your own requires steady handwork and thorough understanding to identify how to troubleshoot tooth filing errors on the way. 

In addition, asking for professional help to sharpen your circular saw blades is not as costly as you think. The price varies on the number of teeth and the blades’ diameter. Online grinding shops charge cheaper than traditional tool grinding shops. 

sharpening circular saw blades

You’ll also have to consider transportation fees when choosing a sharpening service, which is why online grinding options are preferable since it’s cost savvy and more convenient.

Costs of Sharpening Services + Price Differences

A specialist who knows the ins and outs of sharpening a circular saw blade will sharpen your saw for as low as $15, which is way cheaper than purchasing a sharpener. Carbide saw blades cost more and vary from $20 to $60. 

Here’s a table of costs for your reference:

DiameterNumber of TeethCost
250 – 30080 – 96Starts at $20
350108Starts at $24
400108Starts at $25
450108Starts at $26
500140Starts at $38
600144Starts at $40

Circular Saw Blades' Hook Angles, Explained

There are four main angles in a circular saw blade’s intersection: rake angle, front bevel angle, rear levels, and rear corner. The sharpening angles are a vital aid, depending on the saw’s use. 

circular saw blade

For rip saws, adjust the rake angle to a 15 to 20-degree angle. On the other hand, cross saws require only 5 to 10 degrees. Meanwhile, the universal measurement slants at an average of 15 degrees.

When Should I Sharpen My Saw's Blade? And How Do I Know it's Dull?

Certain situations will prompt you to sharpen your saw blade. These are telltale signs that the circular saw blades have gone dull, which calls for a trip to a sharpener.

A common sign your blades may be dull is when smoke arises while in operation and there’s a distinct smell of burnt wood, You can also notice the chainsaw case heats up quickly, which can also be an indicator. 

Circular saws are also easy to use and maneuver, but if you have problems moving the tool around the workpiece, consider detaching the saw blade to check if the saw teeth are still even. 

Often, rough edges call for more grinding, causing an individual saw blade dull faster than the others. 

cordless circular saw

Some woodworking projects will also cause chipping on the blades, and it’s easily recognizable since there are visual representations of curbed and rounded edges. 

Dull blades will cause more human effort when sawing, and when this happens, then sharpening your saw is more cost and labor-efficient. 

There are also woodworking cases where the blade falls, brought about by chipping on nails, and if this is the case, then it may not be worth sharpening anymore, and buying a new one would be more recommended. 

How Often Should I Sharpen My Circular Saw's Blade?

Sharpening your circular saw blade depends on how much you have worked on it and the materials you cut it with. 

Often, woodworking projects require circular saws, and from the frequency of use, you can determine whether the recommended 12 – 18 months before sharpening is still applicable. 

cutting concrete with circular saw

Extra cutter sets are also an efficient alternative if your blades are sharpened with carbide blades. When sharpening a carbide, you may encounter a rough start since it doesn’t sharpen immediately.

To sharpen carbide blades, you must procure diamond wheels, as it requires a dedicated cutter grinder for the blades to sharpen correctly. 

When to Replace a Circular Saw Blade: How Long Do They Last?

Carbide blades get dull more quickly than regular saw blades. After 100 cuts, you should consider checking and inspecting your carbide-tipped blades for possible tearing and wearing since it’s less durable than stainless steel. 

On the other hand, we recommend replacing the entire blade after about 250 cuts if you’re using a regular circular saw.

Carbide-tipped blades are prone to wear, often visible through the round and curved saw blades. Cutting through rough and hard materials may produce more wear and tear, whether stainless steel or carbide saw blade. 

cutting granite with circular saw

When used for coursing through ceramic tile, a diamond blade will ruin the carbide tip, and if this occurs, you’ll have to replace the whole carbide blade as well. 

FAQ

Is it worth sharpening circular saw blades?

Yes, it is worth sharpening circular saw blades. Doing so is paramount to maintaining their efficiency in operations. 

Filing your circular saw blade is cheaper than buying an entire circular saw blade set. A regular trip to the grinding shop will also allow you to conduct regular checks on the blade rather than just assuming whether it’s dull or not. 

How do you sharpen a saw blade by hand?

To sharpen a saw blade by hand, you must procure a blade sharpener. Place the blade accordingly and remove any burrs before cleaning the blade with a soap solution. 

Dry the blades thoroughly to avoid water build-ups. Precise works require you to invest in sandpapers with adjustable angles. 

Conclusion

Most blades will dull easily due to the frequency and intensity of use, and if you love woodworking, then you should be wary of a dull circular blade. 

Now that you know how to sharpen a circular saw blade, woodworking will be easier. But if you think you’re not apt for the extra task, then a trip to the grinding shop may be your best option. 

Robert Johnson is a woodworker who takes joy in sharing his passion for creating to the rest of the world. His brainchild, Sawinery, allowed him to do so as well as connect with other craftsmen. He has since built an enviable workshop for himself and an equally impressive online accomplishment: an extensive resource site serving old timers and novices alike.
Robert Johnson

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