What Happens If You Touch a SawStop Blade?

Alex Davies says a SawStop table saw stops its blade in a fraction of a second when a person touches it, and a touch might leave only a little nick, nothing a band-aid could not handle. An electrical circuit runs through the blade. People conduct electricity, so contact completes the circuit, a microprocessor fires, and a steel brake stops the blade the way a stick in bicycle spokes stops a wheel. The blade is totally wrecked. The finger, hand, face, or arm stays totally fine.

Americans lose two hands worth of fingers to table saws every day. The saws are common and affordable, many home woodworkers use them, and injury rates are high. Warnings say not to stick a finger in, to hold the wood from a distance, and to wear safety goggles, and the warnings do not work well. A plastic guard often covers the blade, but many woodworkers take the guard off because the guard makes the saw harder to use. Steve Gass, an amateur woodworker and a professional patent attorney, was using a table saw and wanted a saw that cannot hurt him, so the design stops the blade at the moment of contact instead of only keeping fingers away.

People who work on safety prefer use error to user error. Use error shifts the blame from the person to the product. People cannot be fixed, warnings do not work, and people make mistakes, but a product can change so the dangerous move is much harder to do by accident.