Another tool I found useful during a recent installation of a solar-powered renewable energy system was the Irwin Unibit® #9 step drill that has what appears to be 14 total steps with two major steps sized (7/8″ and 1-1/8″) for 1/2″ and 3/4″ knockouts in electrical junction boxes and panels. We had more than one instance where an existing box had only 1/2″ KOs, and we needed to bring in some 3/4″ conduit. I suspect there’s an adapter for just this purpose, but the #9 step drill proved very handy and easily enlarged the holes in metal junction boxes. The Irwin 10239 Unibit® has a hex shank, a single-fluted cutting edge, and a SpeedPoint™ self-starting tip. They can be found online for $45 to $50.