Sharp Edge: One Man's Quest To Improve Saw Safety

The SawStop senses an electrical current in the hot dog. i i

The SawStop saw can sense a slight electrical current that human fingers (and hot dogs) create. When it senses the current, the saw triggers a safety brake, which stops the blade in less than 5/1,000th of a second. Courtesy of SawStop hide caption

itoggle caption Courtesy of SawStop
The SawStop senses an electrical current in the hot dog.

The SawStop saw can sense a slight electrical current that human fingers (and hot dogs) create. When it senses the current, the saw triggers a safety brake, which stops the blade in less than 5/1,000th of a second.

Courtesy of SawStop

Table saws are by far the most dangerous tools used by woodworkers and do-it-yourself enthusiasts. Every year around the U.S., more than 3,000 people cut off their fingers or thumbs in table saw accidents, according to data from the Consumer Product Safety Commission. And 30,000 end up in emergency rooms with other injuries.

One entrepreneur has developed a safety device called SawStop that prevents those injuries. But the power tool industry has chosen not to adopt the technology. And because of that, power tool manufacturers now face a growing number of lawsuits.

Lightning Fast Injuries

A table saw has an open spinning blade the size of a dinner plate with sharp, jagged teeth. Often there is no guard attached to protect the person using it. The blade spins so fast, it's hard to see. So, if someone loses concentration for just half a second and puts their hand in the wrong place, they can lose fingers before feeling any pain.

"You can't react fast enough," says Chris Higginbotham, a wood-shop teacher at Forest Grove High School in Oregon. "It's happened before you realize it happened."

A hot dog with a slight nick i i

Although it is left with a slight nick, the hot dog was saved from complete separation by the SawStop. Courtesty of SawStop hide caption

itoggle caption Courtesty of SawStop
A hot dog with a slight nick

Although it is left with a slight nick, the hot dog was saved from complete separation by the SawStop.

Courtesty of SawStop

In his class, about 25 teenagers use table saws and other industrial power tools with sharp blades. That might sound like an accident waiting to happen. And Higginbotham is painfully aware that accidents do happen.

"I had a young man, he paid attention, he did a great job on the safety test ... and he just made a mistake," Higginbotham says. He says his student was making a "dado" cut with an extra thick stack of saw blades on the saw.

In an instant, Higginbotham recalls, his student's index finger was gone up to the middle knuckle, "and there just wasn't anything to sew back on." He adds, "I feel horrible even talking about it now."

Preventing The Loss Of Fingers

Thousands of Americans cut their fingers off every year on table saws. Some cut off three or four fingers. But these days Higginbotham is a lot less worried about accidents because he's using SawStop's table saws in his class. They have a superfast safety-brake mechanism that can sense when the blade makes contact with a finger.

"I absolutely know it saved a kid's thumb," Higginbotham says. "He would have lost his thumb."

Steve Gass, the entrepreneur who invented this safety brake, actually lives just a few miles from the high school. He's a woodworker, a physicist and a patent attorney. NPR first did a story on Gass six years ago when he launched his company. He came to Higginbotham's class to show the students how the saw works.

The Hot Dog Test

It turns out a hot dog has about the same salt and moisture content as a human finger. The SawStop saw induces a very slight electrical current on the blade that is monitored by a computer chip inside the saw. Wood does not conduct electricity — but your finger does. The saw can sense the difference between the two and trigger a safety brake.

When the safety brake is triggered, the blade slams down into the table and away from the person's hand.

"One minute the saw's running full speed with the blade up fairly high, and in a thousandth of a second, it's just gone. It doesn't just stop, the whole blade is gone," Higginbotham says.

Gass demonstrates this using a hot dog, which he places on a piece of wood as if it were a woodworker's finger accidentally placed in the path of the blade. He shoves the wood into the saw, which cuts it, but in 3/1,000ths of a second after the blade touches the hot dog, the safety brake fires.

The hot dog ends up with just a barely perceptible nick in it where the blade grazed the hot dog's skin before the safety brake stopped the saw. At the speed with which Gass was pushing the wood, he says a carpenter would have lost three fingers before he could have reacted. With the safety brake, all you'd need is a bandage.

SawStop Safety System Video

Lack Of Interest From Big Power Tool Companies

Gass invented this technology about 10 years ago. And he's tried ever since to get the big power tool companies to license and use it.

"They came back and said, 'Well, we've looked at it, but we're not interested because safety doesn't sell,' " Gass says, adding that he thought, "What a crazy attitude."

Over the past decade, Gass says, all of the power-tool makers — Black and Decker; Ryobi; Skil, a division of the Robert Bosch Tool Corp.; Makita and others — still haven't adopted this type of safety system. As a result, Gass' startup has been manufacturing saws that include the safety brake.

So far, Gass has documented 700 saved fingers.

"We ended up having to build the saws ourselves to get them out there, and they have sold," Gass says, adding that SawStop has become the No. 1 selling cabinet table saw in the country. "So, we proved how wrong those guys were."

The vast majority of table saws sold still do not have this kind of safety brake. Gass says it's basically like refusing to put airbags in cars. And he says thousands of people are getting needlessly maimed.

The Threat Of Lawsuits

Gass recently won a pretty powerful ally — Stuart Singer, a partner in the law firm Boies, Schiller & Flexner LLP. The Wall Street Journal called this high-profile firm "a litigation powerhouse." The firm successfully sued Microsoft on behalf of the U.S. Justice Department in a famous antitrust case. The firm is joining the SawStop fight by representing dozens of injured people and suing power tool companies.

"We have approximately 50 such cases that are pending in various courts around the United States, and we anticipate more of them will be filed," Singer says. He says the industry has been negligent by not including the SawStop safety system in its saws.

"It is really a shocking lack of concern for the safety of their customers," Singer says. In just a single case, the firm recently won a $1.5 million verdict against the power-tool maker Ryobi.

"Our hope is that we don't have to try 50 cases before we convince the industry that they need to change table saws, and that they need to use an available safety technology to protect customers," Singer says.

Power Tool Companies React

Steve Gass, the inventor of SawStop i i

Physicist, woodworker and patent attorney Steve Gass invented the SawStop 10 years ago, but has had trouble getting the big tool companies to license and use the technology. Courtesty of SawStop hide caption

itoggle caption Courtesty of SawStop
Steve Gass, the inventor of SawStop

Physicist, woodworker and patent attorney Steve Gass invented the SawStop 10 years ago, but has had trouble getting the big tool companies to license and use the technology.

Courtesty of SawStop

The power tool companies argue that they have been making their saws safer. The industry recently adopted a new voluntary standard for a better guard that fits over the saw blade to protect users. And they will be adding what's called a "riving knife," which prevents the wood from pinching the blade and getting thrown back at the person using the saw.

"The members of the Power Tool Institute continue to devote substantial time and resources in the research, development, testing and implementation of improved table saw guard designs and other safety measures," says Susan Young, a spokeswoman for the Power Tool Institute, in a prepared statement. The organization represents the major tool makers.

The Cost Of Safety

Part of the debate boils to down to cost. SawStop says the safety brake system adds about $100 to the manufacturing cost for each saw. On top of that, SawStop would want royalties. On a high-end $3,000 saw, that might not be a big deal. But people can also buy a cheap portable table saw now for around $100. Adding SawStop, or a similar safety system, would probably double that price.

Singer, the attorney for Boies, Schiller & Flexner, says that's what a responsibly built saw should cost. The industry argues that it's unreasonable to force consumers to pay for more safety if they don't want it.

"It could increase the consumer's cost of table saws and reduce the ability of consumers to choose from among safe alternative designs," Young says.

Government Regulator Considering Action

Meanwhile, government regulators could step in. The U.S. Consumer Product Safety Commission's new chairman, Inez Tenenbaum, is taking an interest in SawStop. Gass recently flew to Washington, D.C., with one of his safe table saws to show her his hot dog demonstration.

"I was extremely impressed with how quickly the blade stopped upon contact with human skin," Tenenbaum says. "His SawStop does prevent amputations and maimings from the table saw."

Actually, in 2003, Gass petitioned the CSPC to require this technology on table saws. Tenenbaum would prefer to see the industry adopt the technology voluntarily. But so far that hasn't happened. And in the meantime, according to the CPSC's own data — tens of thousands of people have had their hands mangled and their fingers chopped off on table saws.

"I believe that if we don't see a voluntary standard soon, that we should look at making this product a part of our rule making so we can build that in as part of a mandatory standard," Tenenbaum says. "If we have something that can prevent injury, we need to act upon it now."

The chairman has not yet asked the industry to implement a safety brake such as SawStop as a voluntary standard. If and when Tenenbaum does that, she'd give companies several months to respond before seeking new regulations.

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