I haven't had a chance to test them in the real world but they have been a great help in setting up and attaching small parts to the grill shelves. I was able to get all four corners straight and correct, and the small mounting brackets attached with no problem. At first I was concerned about the magnets affecting my arc so I just set them up so I could position my buttons as far away from the magnets as possible and it worked fine. The only thing that worries me a little is that I don't forget to hide them before sanding because at some point they will surely be covered with steel shavings. But they are magnets. They do.