I used it to trim the oak edge of 3/4 inch plywood. It works well where it can reach and is especially good when you have an edge with no obstacles. But if you're doing this on an assembled piece, like a bookcase or (in my case) kitchen cabinets, the cut will start and end about 2 inches from the crossbar, and you'll have to use a razor or utility knife. to finish the rest. It can grab a 1-1/4" thick edge, but for more you'll need to separate the two halves (don't lose the springs!) and run it along one edge in time. Separating is as easy as the two pieces go comes apart easily but that also means the two halves can easily fall apart in the toolbox and the two springs fall out.While I'm glad I bought it it's practically useless when working with a small piece of an assembled shelf. Oh and it comes with spare blades which is great but the problem is putting spare blades where you can find them as they are not stored in the trimmer but come in a little plastic bag.