The size of a file, stamped on its end, can be hard to read, especially for older folks. The Oregon gauge mentioned is one way to tell files apart (Stihl and Granberg have similar gauges); they are very handy for sorting chains by pitch and gauge.
You can also use a micrometer, drill gauge, etc. I keep new files in their marked boxes, which also protects their brittle edges. In use, I have a separate, marked handle for each size which makes identification easy (use a plastic soda straw to protect the file between uses).
If you use a size-specific file guide, that keeps the files sorted too (wrap with a rag to protect the file in a tool box).
Files are a consumable item, but also a cutting tool. It makes sense to protect their hard, cutting edges from damage, banging around on workbenches, in toolboxes, in trucks, etc.
Philbert
You can also use a micrometer, drill gauge, etc. I keep new files in their marked boxes, which also protects their brittle edges. In use, I have a separate, marked handle for each size which makes identification easy (use a plastic soda straw to protect the file between uses).
If you use a size-specific file guide, that keeps the files sorted too (wrap with a rag to protect the file in a tool box).
Files are a consumable item, but also a cutting tool. It makes sense to protect their hard, cutting edges from damage, banging around on workbenches, in toolboxes, in trucks, etc.
Philbert