Same old saw?

Manufacturers are refining circular saw blades to meet the every-growing demands of contractors. Today’s blades are not your same old saw.

New building materials combined with contractors’ constant push for faster, better tools is changing the look and productivity of today’s circular saw blades.

With the increasing number of saw blade configurations, it can be confusing to select the best blade for the job. But industry experts point out that many users aren’t even aware of the broad line of blades that can help them do their jobs better.

“Contractors put more thought into buying a circular saw than they do in what type of blade they put on it,” says Sal Locascio of Primark Tool Group. “If you add up the cost of blades a saw uses over its lifetime, the blade cost far exceeds the cost of the saw. So it makes sense to make sure you have selected the right blade for your job at hand.”

Terry Rakosky, DeWalt’s director of marketing for professional circular saw blades, concurs. “Selecting the best circular saw blade for the job will give you longest blade life and best cutting efficiency.”

What contractors really want
On circular saws, Locascio says contractors rank durability as their No. 1 criteria for blade selection. That’s followed by speed and ease and quality of cut.

To achieve these performance goals, blade engineers balance carbide type with plate designs that use specific hook angles and gullet sizes.

Depending on the application, carbide-tipped blades will stay sharp up to 30 times longer than steel blades. However, they cost more than value-priced or economy blades.

The experts agree you should look at the overall cost per cut instead of the cost per blade. “If you will be doing demolition work, you may choose a lower-cost blade because the embedded nails may damage a good blade,” Rakosky says. Or, use a blade specially designed to withstand the impact of cutting nails for demolition work.

Blade design and how it affects cutting
Engineers have used some interesting saw blade designs to help the blade perform better in certain jobs. Here are some of the ways they adapt the blades for specific jobs.

Carbide tips: The tip of the blade tooth is usually made of grade C2 or C3 carbide which offers a good trade-off between durability and sharpness.

“C4 is a harder carbide, but is more brittle and has a greater chance of chipping or breaking off if the saw hits a nail or even a hard knot in the wood,” says Rakosky.

Plate design: Saw makers get more durability out of blades by adding a high shoulder on the back of the saw’s tooth. “This puts steel behind the carbide-tipped tooth for good support,” Rakosky says.

Heat treatment: Professional-quality blades are heat-treated to remain rigid, even as heat builds up during cutting and prevents warping as the blade cools.

Expansion slots: Usually four interruptions in the blade’s surface, these slots help dissipate heat. “A cooler running blade reduces carbide wear, which translates to longer blade life,” Rakosky says.

Thinner kerf: The kerf, which is the width of the cut a blade makes, affects cutting speed and how the blade feels as it’s cutting. “A thinner kerf allows faster, smoother cutting. Thin-kerf blades can make difficult cuts such as arcs easier to do. They also enhance under-powered saw performance,” Rakosky says.

Coatings: Non-stick coatings help prevent resin or pitch build-up. “It keeps the blade clean and keeps chips from binding behind the tooth and filling the blade’s gullet,” Rakosky says. The coatings also discourage corrosion.

Cordless circular saws are gaining popularity and users want different performance characteristics when compared with corded saw blades.

Cordless saw needs
Because power is an issue, cuts per charge is an important factor in blade selection, says Rakosky. Cordless circular saw blades have ultra-narrow kerfs which cut more efficiently and use less power to make cuts. Cordless saw blades usually have an aggressive hook angle so the blade cuts quickly and uses less power.

“We have had owners say their cordless saw wasn’t holding a charge as well as when it was new because they were getting fewer cuts per charge. Instead, they were experiencing the effect of a worn blade. If the saw blade is worn, it takes more power to make a cut. A sharp blade will give you more cuts per charge than a dull one so it’s importnat to use sharp blades to maximize cuts per charge,” Rakosky says.

With so many blade designs available, how do you select the right blade for a job? Locascio says distributor salespeople can be your best source of information.

“They can share which blades sell best, comments others have made about certain blade types in applications and what they have learned from manufacturer training. They should have some good advice,” he says.

 Published in the July/August 2001 issue of Contractor Tools and Supplies magazine.

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