I put a TI flat B .137 on my Bongo and it was too thick for the nut. It popped the edge of the nut off. See pictures. The string is in no danger of sliding off the nut. It is still in a groove under it, plus it is pulled slightly toward the center. I found the little piece of plastic that broke off. It can be glued back on to the nut, but obviously the nut would then need to be filed to prevent this from happening again. Should I just leave it like it is, or do I really need to have a perfect nut?