Files have become another victim of "cheap manufacturing"...... There was a time when all I would recommend were Nicholson files, but they are becoming hit-n-miss...... even Nicholson has caved to the cheaper manufacturing gig. I've purchase several Nicholson files over the past year, and noticed that some are "made in USA", and others are marked as Made in XXXXXX (various other locations). Those made in the US seem to be the "good" ones, and those with other markings are very obviously of much lower quality.
OK, that being said, I've been using these files for a while now:
https://www.homedepot.com/p/Husky-Multi-Purpose-File-Set-10-Piece-H10PCFS/206313272
The reason is because I've become frustrated with the "cheapness" of files, and this set is "lifetime warranty"... even if they wear out. I purchased two sets, and am currently on set #s 12-13 from returning them under warranty. This set contains most of the files you will need for fitting various type/styles of guards. I also have several smaller square files, that are 5/32" square or smaller.... these are essential for me when it comes to slotted guards, and are often used with hidden tang guards. These are sometimes difficult to find, and I've picked mine up when/where I can locate them.