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by J.Peter

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filesIt is really amazing how many files I have for how little I use them. Per request I am going to discuss the files I use as a watchmaker. On a regular basis I use my 8″ No. 2 Cut file and one or two of my escapement files, the rest sit in my drawer. If I were doing more custom work or parts manufacturing I would use them a lot more. High Quality files are important. I recommend Grobet Vallorbe – as they say, if it’s got the rabbit it is a good file 🙂

Larger Files I use the larger files mostly for tool making, although I find myself using the large No. 2 file for shortening case tubes, case work and bracelet work, like forming rivets and shortening pins. For serious work you would want an aggressive file like the 8 inch No. 2 file A good number 4 file and a 5 or 6 for fine work. You would also want at least one half round file, mine is pretty coarse, it is a number 3. The numbering system represents an old system dating back to 1812 and represents the number of teeth per inch on a sliding scale proportionate to the overall length of the file. For in depth information about files you can visit Grobet USA.

Escapement filesEscapement files are small fine files (presumably for use in constructing the parts of an escapement). I have the standard set of 12 swiss made files from Vallorbe with cut 4. These files are also very useful for skeletonizing work, or any small delicate work. These files are sometimes referred to as needle files. Their is a light difference. Escapement files have square handles, needle files have round (usually with knurling). Escapement files are slightly finer: an escapement file with cut 4 has 142 teeth per inch and a needle file has 117.

Euro Tool FilesWhen I was in watchmaking school I was doing a lot of filing and I wanted a set of more course needle files fast so I bought this set of Euro Tool files made in India with a Cut of 0. That’s when I learned how nice my other files were. It pays to buy the nice stuff. But they are acceptable for course work, assuming you’re going to go back and clean up with a finer file.

If you want really clean edges you may want to go and remove the file marks, an emery stick (see top pic) or some lapping film (self-adhesive from 3M) on a small piece of brass looks really well. In fact lapping film on a brass slip is really good for polishing beveled edges.

If what you want to do is skeletonize a watch movement, most people start with a flex shaft tool, dremel tool, or drill press to rough out the basic shape then go in with a jewelers saw and escapement files to fine tune it. Finishing it all up with some lapping film on a perfectly flat surface, actually the back side of a barrette file can work nicely. Also the file edge of a watchmaker’s pivot burnisher works well for this. Some people use Diamond needle files or Diamond escapement files but I don’t have any experience with either.

There are of course many, many more types of files. All of the ones I mention above are cross cut files some of them have a safe edge others do not. These are simply the ones I use. A final note on safe edges. If you want to file crisp 90 degree corners you should dress your safe edge, typically the cuts don’t go all the way to the edge of the file so relying on the factory safe edge will give you a slightly rounded corner. To produce sharp 90 degree corners prepare at least one of your files by stoning down the safe edge all the way in until the teeth come right to this edge. This can be a tedious process. It took me most of a day to prepare my 5 inch number 5 file’s edge. But it would have taken less if I had used the diamond lap – alas they didn’t allow us such things in watchmaking school 🙂

Oh yes, one more thing. Keep your files clean and dry. You don’t really want oil on them because this will cause them to clog. In a humid climate you might store them inside of a very lightly oiled rag or with some of those silica moisture absorbing packets. Some people use wax in them to keep them from clogging. When they do clog use a file card to remove debris. Move the card across the file following the cuts.

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