Re: hand file
I'm a flutemaker. Our instruments are made of sterling silver and 14k gold. No plating. From the beginning of flutes made with metal key work, the file, burnishers, sandpaper and scrapers have been our primary tools. Grinding wheels became a prominent part of our production in the 1970s. That said, Swiss (Suisse) precision files have always been the best. Grobet was the first choice, followed by others like Nicholson. Whats changed in files is that Grobet files are now marked, not stamped, but etched, Made In Italy. And they are not as sharp as I believe they once were. What I recently learned, after 50 years in this business, is that, I think, Grobet never manufactured files themselves, but contracted it out. I recently came upon a new to me maker, Glardon Vallorbe. See them here at this supplier. https://www.ottofrei.com/
If you go to their website, there is a short video of files being made. Very worthwhile to see.
Jewelry making supply companies are important to us, as it is akin to what we do. Swiss precision files, from needle to Mill bastard are very expensive now. Especially the finer cuts like #4 & #6. some styles have disappeared with the advent of other forms of surface finishing.
I hope this is helpful to everyone. Happy to answer any questions in a new thread as i don't wish to highjack this one.
Best to everyone on this holiday weekend,
PS ultrasonic cleaners are great for cleaning files too.