How to Sharpen a Circular Saw Blade

Posted by John Rennie on

Circular saws are incredibly useful tools that can be used for all manner of DIY projects. You probably use yours multiple times throughout the year to cut various items, after a while, the blade will get dull. Rather than replacing it, you can get the most out of each blade by sharpening it. If you’re not sure how to sharpen a circular saw blade, we’ve put together this handy guide. 

Signs a saw blade needs sharpening

Before you start sharpening your blades, it’s best to make sure they definitely need doing first. Signs that your blade needs sharpening include:

  • Poor cutting finish – dull blades can cause wood and metal to chip, resulting in a poor finish that is not smooth or neat
  • More effort required – an effective saw blade should cut through hard materials like a knife through butter, but a dull blade will require far more effort on your part
  • Burn marks – dull blades require you to apply more pressure to the saw to make the cut and this creates friction which can then lead to unsightly burn marks
  • Burning smell – if you smell burning when using your circular saw, it is likely that a dull blade is forcing the motor to work harder, creating a burning smell, or even smoke
  • Dirt – saw blades should be shiny. If yours is not, it probably needs a clean and sharpening to prevent friction

If you notice any of the above signs, it’s likely high time to sharpen your blade. Not every blade can be sharpened, though. Sometimes, replacement saw blades are needed. Signs you need a replacement rather than a sharpener include:

  • Warped teeth
  • Chipped teeth
  • Missing teeth
  • Rounded teeth

For the best performance, if you notice any of the above damages, it’s best to replace your TCT circular wood saw blades

How to sharpen a saw blade

Once you’ve correctly identified saw blade sharpening as the best option for you, you need to learn how to do it. Carbide saw blades can be easily damaged, so a lot of people opt to have them done professionally instead. That being said, it is possible to sharpen saw blades yourself and, aside from precision and patience, it’s not as hard as you might think. 

You will need:

  • Taper file
  • Vice

You may choose to wear gloves for added protection. Once you’ve got everything you need, you can begin. 

  1. Remove the saw blade from the saw and secure it in the vice
  2. Make a mark on the tooth you’re beginning with
  3. Lay the taper file flat at a 90˚ angle underneath the saw tooth
  4. Hold the file with one hand at the base and one hand on the tip
  5. Move the file horizontally – two to four strokes should be sufficient
  6. Repeat the step on the following teeth until you get back to the first one

Taper files are effective circular saw blade sharpener tools, and it is an effective method that is easy to pick up, but it can be time-consuming. If you don’t have the time, or if you have an expensive blade that you want to preserve, it might be worth looking at getting it sharpened professionally. 

Why sharpen saw blades?

You might be wondering if it’s easier to just buy new saw blades instead of going through the hassle of sharpening your existing ones. Whether you use your saw regularly or occasionally, knowing how to sharpen TCT circular saw blades can save you money. As a general rule of thumb, blades can be sharpened three times before they need replacing entirely. 

Depending on the type of blades you purchase, this could save you a considerable amount. Those who don’t use their saws too often can likely go a year or more until they need to sharpen it, but those who use it regularly can usually get a few weeks out of each sharp blade. 

Regardless, every blade needs to be clean. 

How to clean saw blades 

A lot of saw blades appear dull because they are dirty. As previously mentioned, blades should be shiny for the very best results. If yours is looking tinted or grimy, you will need to clean it, and here’s how:

  1. Fill a container with one part degreaser (Simple Green is popular as it is biodegradable and works exceptionally well) and two parts water
  2. Remove the blade from the saw and leave it to soak in the container for a few minutes
  3. Use a toothbrush to scrub excess debris, residue and pitch from the saw blade
  4. Remove the blade and rinse it
  5. Dry the blade with a paper towel
  6. Coat the saw blade with an anti-rusting agent such as WD-40

The above steps should keep your saw blades in fine condition and may reduce the number of times you need to sharpen or replace the blades. 

Replacement saw blades

If you’ve sharpened your circular saw blades multiple times and it’s time to replace them, we can help. Please browse our range of saw blades, or call us on 0161 477 9577 for advice and help. 


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