One of the things most folks who fix things have is a file, or two, or a bunch, depending on what you need them for. They come in all shapes and sizes depending on their purpose. Files are made from very hard steel. One would think that they would be hard to damage, but they will dull. Particularly if, like me, you store them all together in a drawer of a tool box. You really want to protect them from banging into each other. It does them no good at all. I spend a couple of pennies and a few minutes to protect them from each other. Here is another of my "Doc's Little docs" on how I do it.