Hand Tools Archive
Like they do on the internet. This is a high hardness file mule mostly flat (slightly convex) bevel at around 15 degrees total. Needless to say, it didn't hold up with just a buffed edge, but with a secondary of about 20 per side and buffing, it held up.
The idea is to put the nail on a metal surface and tap the spine of the mule with a metal hammer.
I don't think file steel hammered at low temp will have an issue in the long term in a wood chisel....and finish nails are really soft.