I'm not a bass player, I'm a sax player, but I have a MIM Fender Jazz Bass 5-String that I picked up for writing songs and recording at home.
I couldn't find an Allen wrench that would fit so I went and bought a new, non-metric, set.
I found that the 1/16" Allen wrench does not fit in the bridge adjusters. It's a little too big. The next smallest size I have is too small, so I'm going to have to go pick up a metric set and hope the 1.5mm will do the trick. The Fender site posted above says 1/16" fits MOST
MIM basses. I guess I have one of the other kind.
At least when I'm all done I'll have two nice sets of wrenches.