I had to file some to fit the crescent shaped cutouts found in most 14 bolt spindle nuts. Luckily it wasn't heat treated so it wasn't hard to get it working. Since they are actually only needed to set the bearing preload when installing the hub, I don't see the lack of heat treatment as a real problem. There are a few square eyelet heads that will work, but they have smaller square eyelets so they just don't knit neatly. This isn't one of them.