Fit perfectly on my 4 1/2" Bosch angle grinder with a large center hole. However, they do not fit on my 4" Craftsman grinder as it has a smaller hole. They have many razor-sharp teeth. I like the curved shape, which allows for very precise shaping of the wood when cutting an edge on a guitar body, for example. If you have a variable speed grinder this is even more effective, but a standard light touch coffee grinder will get the job done. You might want to fine-tune it with hand files as you get closer to the edge, especially if you're shooting on a flatter surface. It will be a welcome addition to your arsenal and will meet your unique woodworking needs.