Ben Blatt is a reporter for The Upshot and an amateur woodworker who once received stitches for a band saw injury. What’s it worth to you to minimize the risk of cutting off a finger? $300? $600?

For woodworkers, the table saw stands as both a revered tool and a potential danger. One saw, SawStop, uses an innovative technology to prevent the saw from cutting more than wood. The feds are now ...