A rooter functions as a small scraping or cutting blade designed to clear out narrow channels, dadoes, or the bottoms of grooves. Often set into a block or used alongside a plane, it ensures the floor of a recess is flat and cut to a uniform depth.
Heard on the job
Grab the rooter and clean out the bottom of that hinge mortise so it sits flush.
Insider tip
Keep the blade perfectly square and take very light passes to avoid tearing out the bottom of the groove.