How Do I Know If My Table Saw Blade Is Dull (6 Simple Ways)

Table saws and circular saws are indispensable tools in the workshop of both professional craftsmen and serious DIYers. With a sharp saw blade, you cut the best quality, and you can work faster and more accurately. However, the more you make saw cuts, the duller your knife becomes. Without you really noticing it, the quality deteriorates slightly with each cut. But how do I know if my table saw blade is dull, and how do you know when to replace the saw blade? Well, here are a few signs your saw blade is dull:

• The blade cuts slower than normal
• There is more resistance and the saw blade tends to jam
• The blade will cause more chipping than usual
• It’s getting harder to follow a line
• The noise level of the saw and saw blade increases.
• The blade will produce burn marks on the wood and may start to smoke.

Have you noticed any of these, or has your circular saw been having trouble cutting lately? Then in this article, you can read more about recognizing these problems, their dangers, and what to do if this is the case.

Disclosure: At zero cost to you, I may get commissions for purchases made through links in this post. I earn from qualifying purchases as an Amazon associate. Products featured are selected based on quality, performance, and reputation, regardless of affiliate relationships.

Why Is It Important to Replace a Dull Saw Blade in Time?

The most important reason to know when your saw blade is dull is your safety. OK, replacing or sharpening a saw blade isn’t cheap, but your health, on the other hand, is worth a lot more.

As the blade wears, the cutting will generate more heat. Excessive heat will warp the saw blade and will lead to increased vibrations during cutting.

These vibrations can cause the saw to become uncontrollable or the blade to lock in the cuts, causing table saw kickback. This can lead to serious injury, limb amputation, or even death.

In addition to the increased safety risk, a dull saw blade can also lead to inaccurate cuts that can completely screw up your work.

A last essential reason to replace the saw blade in time is to prevent overloading the saw table or circular saw. Due to a dull saw blade, the machine will have to place more force on the saw blade, resulting in wear.

What Is the Average Lifespan of a Saw Blade?

To know how long a saw blade will last, you have to look at the number of hours that the saw blade has cut and the quality of the saw blade. For example, the lowest quality saw blade will be dull after 20 hours, while an exceptional quality saw blade can last up to 100 hours or more.

The lifespan of your saw blade will also depend on whether you use it for the right purposes and how well you maintain it. More on this later in this article.

If you are not sure which saw blade you need for your workshop and the projects you are working on, you can find a lot of inspiration in my article Understanding Table Saw Blades | Always Find The Perfect One.

Will Cleaning a Saw Blade Increase the Lifespan?

Yes, cleaning a saw blade will make it last longer and less likely to become blunt. Poor cutting is often the result of a dirty blade. Sometimes your saw blade will show all the signs of wear, but all it takes is a good cleaning to get a cut almost like new.

Wood resins stick to the saw blade during cutting. After collecting enough residue on the saw blade, it causes the characteristics of a dull saw blade to appear. If you do not remove these resins, they will blunt the leaf faster over time. It is therefore important to regularly clean the saw blade.

How Do You Clean a Saw Blade?

Cleaning a dirty saw blade is easy and a good way to get it sawing like new again. Soak the blade in a saw blade cleaner such as the CMT Table saw blade and router bit cleaner for 15-20 minutes. This cleaner is strong enough to remove all resin residue in a short period of time.

After soaking, you can brush the saw blade clean. I already found that an old toothbrush works very well (don’t use your own toothbrush, of course, I don’t know what effect it will have). When brushing it is good to focus mainly on the teeth, but of course, it is recommended to brush all surfaces.

After brushing, rinse the blade with plenty of water and dry it completely. Drying is an important step to prevent rusting, so pay enough attention to it.

After completing these steps, put the blade back on your saw and perform a trial cut to see if the cutting performance has improved. If the cutting has not improved, the blade must still be sharpened or replaced.
Go to my in depth article to Learn How To Clean Table Saw Blades For Best Cutting (5 Simple Steps)

Precautions to Take When Saw Blade Cleaning

Many of the blade cleaners on the market have very high pH levels. Although they are powerful bases and not acids, they can nonetheless endanger your health in the same way.

Strong bases corrode metals. Some cleansers for saw blades may even be very caustic. They are made with a powerful solution that can quickly clean a saw blade while also breaking down brass, copper, and aluminum. Some metals deteriorate more slowly than others. Be cautious if you don’t know what type of material your saw blade is made of.

When cleaning saw blades, always use safety glasses to prevent product splashes from getting into your eyes.
When working with chemicals, gloves are a must. When cleaning a saw blade, though, be sure to put on gloves that can withstand chemicals. By doing this, you can protect your hands and skin against harmful reactions including chemical burns.

When using these products to clean a saw blade, it is also a good idea to use eye, nose, and mouth protection. In the vicinity of where you are cleaning the saw blade, you may throw a few drops of the cleaning solutions into the air. Those little droplets run the risk of entering your lungs through inhalation.

How Do I Know If My Table Saw Blade Is Dull

There are several red flags telling you it’s time to replace or sharpen your saw blade, you just need to know what to look for. Below is a list of the key features to remember and look forward to.

Note, that many of these red flags can also indicate that the saw blade needs cleaning. Sometimes a simple cleaning of your saw blade can make it look new again.

The Blade Cuts Slower Than Normal

Because the teeth of the table saw are no longer as sharp, they will cut through the wood less well. This will reduce the speed of the table saw or circular saw. If you know your machine well, you will hear that it will no longer run at full speed. Because the saw blade will turn less quickly, it will reduce your work speed, but also increase the risk of accidents.

There Is More Resistance and the Saw Blade Tends to Jam

With a sharp blade, there should be little to no resistance as you push through the cut. The blade can be dull if it feels like it needs more force to cut than when it was new or if it seems to get stuck in certain places when cutting. When utilizing a table saw, all that should be required is for the workpiece to be slid across the saw’s tabletop and past the blade.

The Blade Will Cause More Chipping Than Usual

The blade tears out more easily and chips more frequently as it gets older. A sharp blade may cut through the fibers of wood to produce clean cuts. Instead, a dull saw blade chips and shreds them, causing tearout. The blade is probably worn down if you notice tearout after each cut.
More info on How To Avoid Tearout When Cutting (9 Powerful Tips) in this article.

It’s Getting Harder to Follow a Line

Blades that are dull do not follow cut lines cleanly. A dull saw blade requires more force to cut through the object it is cutting. When the saw blade is dull, it prefers to take the easiest route. This results in erroneous cuts. It’s possible that your blade is worn out if your cuts are ragged or imprecise.

The Noise Level of the Saw and Saw Blade Increases.

As I mentioned earlier in this article, if you know your saw well, you will know the usual noises it makes when cutting wood. But if the sound changes, or it sounds like the motor is overloading when making a cut, that could be a sign of a dull blade.

At any change you hear in the sound it makes, please stop the tool immediately and check what the problem is, even if it’s not due to the blade that is dull.

The Blade Will Produce Burn Marks on the Wood and May Start to Smoke.

Burn marks are typical, but they can also be a sign of a blade that needs to be replaced. A dull saw blade requires more effort and time to make a cut. Burn marks are produced as a result of the increased friction and built-up heat with the workpiece. So if you have more burn marks than usual, check the sharpness of the blade, there is a great chance it will be dull.

Other Signs Your Saw Blade Needs to Be Replaced

In addition to the saw blade’s gradual wear, there are additional factors that may persuade you to replace the saw blade for a better, safer cut. In order to avoid these potential issues, always perform a visual inspection of the saw blade at the beginning of each working day.

Look for wear and damage indications. As a totally missing tooth on a saw blade cannot be restored, broken and missing teeth are obvious indications that your blade needs to be replaced.

Compare the saw blade to another blade of a similar size and quality that you are familiar with. Expert woodworkers frequently purchase multiples of the same blades. One sheet serves as your primary, while the second one serves as a backup that you occasionally use. It is simple to see when your primary saw blade is dull because of this. Additionally, a good knife is always available for use.

Take note of the variations in the two blades’ teeth when contrasting them. If the teeth on your primary blade differ significantly from those on your backup, your primary blade is likely worn out. Change the saw’s backup blade, then have the main blade sharpened or replaced. When you receive the freshly sharpened blade back, it serves as a backup. By doing this, you may compare your primary blade with a backup blade that is in good shape at all times.

Saw blades with pronounced flaking and collection of debris
Check the carbide tips of the blade’s teeth by closely inspecting it with a flashlight. When you closely inspect the blade, the carbide tooth tips should reflect light. If the carbide tip appears to reflect light differently than the rest of the tooth, it has broken off. Sharpen the blade if several of the carbide tips are missing.

Look for teeth that have chips or are rounded. Examine the teeth. If numerous of them seem chipped in relation to the others, it’s time to sharpen or replace the saw blade. The most common place for teeth to chip is at their carbide tips. In my blog post Understanding Table Saw Blades | Always Find The Perfect One, I go into further detail regarding the various saw blade tooth shapes.

How Do I Know If My Table Saw Blade Is Dull – Conclusion

If you work with a saw blade, you know that it will not last forever. As you can read in this article, there are several reasons that require replacing a table saw blade. Doing that can solve some of table saw problems that are listed in this article. If you’re wondering, “how do I know if my table saw blade is dull”, the various red flags I’ve discussed in this article will help you spot and replace a dull saw blade faster in the future. That way, you will be able to work better and safer.

Is It Worth Sharpening Circular Saw Blades?

Now that you can determine if your table saw blade is blunt, it’s time to move on to the next step. Are you going to replace the saw blade or have it sharpened? To help you with that and avoid unnecessary costs, I wrote the article, is it worth sharpening table saw blades, where you will find all the information you need.