Even though there are a few differences between American and Swiss pattern files, such as range of sizes and the way that their coarseness is described, they are still files and it would be impossible to tell them apart at a glance.
That means that they are generally interchangeable. If you’re looking for an American pattern second cut flat file to smooth off the edge of a piece of metal, you’ll find that a Swiss pattern grade 0 flat file will do the job just as well. In fact, it would be just like using the same file!
Different types of file can sometimes be interchangeable as well – the most important thing is that your file fits into the space where you need to use it, and that you choose the right coarseness for the job. The ‘nationality’ of a file should not be a consideration when deciding which tool to choose.
When it comes down to it, there’s very little difference between Swiss and American pattern files. If you didn’t know which type of file you had, it wouldn’t affect your ability to use the tool.
American pattern files are made in larger sizes than Swiss pattern files, and all saw files are American pattern.
Some shapes of file are exclusively Swiss and others are exclusively American. This information is included in each of the individual file guides.
Engineer’s files: potential confusion
It’s possible that you might see a Swiss pattern file referred to as an engineer’s file, even though this is an alternative name for an American pattern file!
The reason for this is that engineer’s files are designed to be used for shaping and finishing, irrespective of where they were made.
If this happens, don’t worry. The chances are that you will have been looking for a file to do some shaping or finishing work anyway, so just look at the size and coarseness of the file and ignore whether it is Swiss or American!