Replacing Circular Saw Blades
The circular saw is a mainstay to any workshop or garage. It's most commonly used to cut straight lines in lumber; though a simple tool, it's been an unsung hero of the DIYer for many years.
No matter how reliable your circular saw is, at some point, you're going to need to perform some maintenance to keep it running at its best. This includes replacing the blades.
Like any other maintenance issue, it takes a careful eye to monitor and identify problems with your best circular saw blade. It's an important skill to learn not just for the life of your machine, but for your own safety and welfare, too; a dull or broken blade can lead to serious accidents, after all.
So when is it time to change the blade? Let's find out.
The Blade is Getting Dull
There are a few reasons your blade could need replacing, the most obvious of which is the blade has gone dull.
Depending on the quality of the circular saw blade, it can last between 12 and 120 hours of continuous use. How long the blades last also depends on what materials the saw is being used to cut.
Symptoms of Dullness
How do you know when the blade goes dull? This depends a little bit on the blade. If you have a carbide-tipped or steel-tipped blade, you should look out for:
- The blade will cut slower than usual
- The blade may bind up mid-cut
- The cut may not be as clean, meaning the blade may leave more tears in the material or cause it to chip
- The blade may leave burn or friction marks in wood
- The blade may start to smoke when cutting through wood
Diamond-edged blades have different dulling signals:
- The blade may glaze over. This means the bond holding the diamonds on the edge of the blade has melted over the diamond edge.
- The blade's edge will look smooth. This indicates the diamonds have been worn away
- Like carbide or steel blades, diamond blades will slow down or completely bind up mid-cut when the blade gets dull.
Cutting Different Materials Or Cuts
Circular saws are especially handy in the fact that they can cut multiple materials. With that said, you'll absolutely want to replace or switch your blade if you're going to be cutting different materials.
For example, let's say one day you're cutting wood and the next you're cutting stone. A blade meant for wood isn't going to do well on granite and could pose a hazard to you and your saw.
If you don't have two different saws and you're going to saw two different materials, it's wise to change the blade.
Additionally, if you are creating different S, it may be wise to have a different blade for each cut so that the wear remains consistent.
How to Replace the Blade
Replacing the circular saw blade is a relatively simple process.
First, unplug the saw or remove the battery if this is a cordless circular saw. Push down on the arbor-lock button and rotate the blade until the locking mechanism activates.
Using the blade wrench, remove the arbor nut holding the blade in place. Then, gently draw back the blade guard and carefully remove the blade. Slide the new blade into place and make sure the saw teeth face the direction of the rotation.
If you need help finding that info, check your instruction book or just look on the side of the saw's blade guard; there should be an arrow pointing in the right direction.
Use the blade wrench to tighten the arbor nut. Don't over-tighten as it will make it too difficult to remove the next time you need to change the blade.
Sharpening and Cleaning Blades
Sometimes circular saw blades don't necessarily need to be replaced when they can potentially be sharpened or cleaned to get a little more life out of them.
If you have a steel or carbide blade, there's a pretty good chance that the blade is only dull because it needs to be cleaned. This just comes with regular wear and tear and can be pretty simple to solve.
Remove the blade using the instructions above (be careful; safety first!) and soak the blade in an all-purpose cleaner. Carefully brush the blade clean.
If the blade is still acting as if it's dull, it might be time to sharpen it.
Steel-tipped blades are pretty easy to sharpen as you'll only need a hand file or mechanical blade sharpener to get the job done.
Carbide blades are a bit trickier since the blades would need to be ground at specific angles with a diamond grinding wheel. If you have a carbide circular saw blade, it would be best to get the blades professionally sharpened. This usually runs between $0.25 and $0.50 per tooth, so it may or may not be worth it to you to sharpen rather than replace.
The good news about diamond-edged blades is on table-mounted miter or tile saws, these blades can easily be sharpened and deglazed to breathe new life into the edges. The bad news about diamond-edged blades is the handheld circular saw blade variety typically needs to be replaced and can't necessarily be effectively sharpened.
To Wrap It Up...
Dull or dirty circular saw blades are just a fact of life; no blade lasts forever. However, there are things you can potentially do to extend the life of your blade.
If you have a steel-tipped blade, you might just need a simple cleaning with an all-purpose cleaner or a sharpening session and you'll be good to go. Other blade types need to be handled professionally, which may or may not be cheaper than getting a new blade.
If you choose to replace your blade, remember to excercise caution and work carefully. It's not a difficult process, but it could lead to potential injury as you're dealing with sharp blades.
Look for the signs of dullness, try more conservative treatments accordingly, and if that doesn't work, replacing the blade is easy and quick.
Resources— Craftsman, Family Handyman
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