How to Sharpen a Blade

Circular saw blades, like any other kind of blade, can get dull after repeated use, as the straight metal edges of the bevels wear down. And, like any other kind of blade, they can be made sharp again by filing the edges back into the metal. The complication with circular saw blades is their shape, since there's no beginning and end to a circle, but that's easy to remedy with a pencil mark to show when you've gone all the way around. This sharpening method only takes a few minutes and can return your basic saw blade to a like-new condition.

Things You'll Need

• Vise with rubber or wood pads (to prevent damaging the blade) Pencil Small three-sided file Eye protection

Instructions

1. Remove your saw blade from the saw (generally, it's a matter of using a wrench to loosen a bolt at the center). Put the blade in your vise, gripping it just below the center hole.

2. Make a pencil mark on one of the teeth so you'll know when you've gone all the way around the blade.

3. Position the tip of your file in the well of the first beveled tooth edge that's facing you. (The directions of the bevels will alternate.) Run the file forward in a gentle but firm stroke, in the same direction as the bevel, for the full length of the file, moving upward along the tooth and off the point. Lift the file, return the tip to its original position, and repeat two more times, filing in the same direction each time.

4. Repeat the process on each of the bevels facing you, skipping each of the ones in between that are facing the other side. Continue until you get to the vise, then loosen the vise and rotate the blade so you can get at the rest of the teeth. Continue sharpening every other tooth until you get back to your pencil mark.

5. Loosen the vise, flip the blade so the other side is facing you, and repeat the whole process on the bevels from the other side.

Tips & Warnings

• This method isn't recommended for carbide-tipped blades, as the metal in them is likely to be harder than your file.

• Make sure to unplug your circular saw before removing the blade. Wear eye protection when using a file.

References

• More information is available here.