What causes a broken carbide tooth?

stack of sawsA tip can break from the face all the way to the braze if it impacts something. Acute points are likely to fracture compared to low durable angles, and a narrow pointed corner may break off. If blades are piled up, sliding around can cause a broken tooth. It's not uncommon to drop or damage one mounting it. Don't set it directly on a table saw or lean it upright without padding beneath to protect tips from breaking.

A carbide tip is attached by silver soldering. Brazing melts a strip of metal between a tip and its seat. The solder in a good braze has no lumps or voids. If brazing is adequate, it is unlikely for a whole one to break completely away from its attachment. During impact, it is not unusual for a little bit of a corner to break off while most of the tip remains firmly brazed.

A partly chipped tooth doesn't cut much, but it may not be a total loss. It can still carry out dust. Unless the entire tip is totally missing including the steel, what's left of it can still stop the next one from biting too deep and help discourage overfeeding. Even if you didn't replace a chipped tip, it wouldn't necessarily be as urgent as a bent tooth. A blade with even one slightly bent tooth is likely to demand immediate attention. To detect bent tips, unplug the unit and sight along the rim. Slowly turn it manually and examine it thoroughly, especially near the expansion slots. Look closely for any slight irregularity. If you discover a damaged one, put a bold mark next to it. If you point out the one that needs repair, a professional may be able to meticulously re-align a bent tooth and return the blade to harmonious function.

Some tips are brittle, and you may notice top edges chipping. Abrasive materials are likely to cause such problems. It is not always so practical to replace a broken tip as it is to take effective steps to dampen vibration. Expose fewer tips above the stock. As a thin gauge plate vibrates, its tips are vulnerable to getting cracked. A thick, tensioned industrial one is stable; this helps to avoid broken teeth. After hitting a nail, you might get a few broken or missing teeth in a row. It's possible to retip a broken tooth with a replacement as strong as before. A retip is done using the same technique and equipment as when the original was made. This customized repair is labor intensive. If several fracture, replacing tips may not be worthwhile.

Protect blades

If you stack circular saws between uses, take care to protect them with layers of cardboard so they can't touch. If humidity is high, a light coat of paste wax or WD-40 gives protection from oxidation.

An individual rubber ring can protect it while not in use. It is easily homemade out of 1/2 in. dia. tubing. Cut a length to circle it, adding a generous overlap. Slit it lengthwise and wrap the circumference. The overlapped ends cling together.

Another way of protecting the edge is to dip it in melted soy plastic. The coating is tough, but you can peel it off by hand like wax. Save it to re-melt and re-use.

Homemade carrier

saw storage carrierTo carry saws, you can make a homemade tote. Measure the largest one, and get a board 2 in. wider and 5 in. taller. For a handle, cut out a 4 by 1 in. slot one in. from the top. Locate the board's midline. Add 2 inches to the radius. Then, starting at the bottom, go that far up the center line to drill a 3/8 in. hole. You will need a 3/8 bolt as tall as the pile, plus at least 1 inch. Insert it through your carrier and secure the stack by a washer and wing nut.


Find answers to frequently asked questions on using circular saw blades and taking care of them. Read about basic woodworking techniques. Get quick and easy tips that save time and conserve materials. Learn how to solve some of the most common problems encountered in both beginning and advanced woodworking.