I was taking a bunch of tool holders out of service the other day, and I
couldn't get the set screw out of one in order to push the tool out. It
felt like the set screw was rounded out, but the set screw looks ok, and
a long handle hex key seemed to feel ok in the hole.

This morning after firing up the shop and getting jobs cutting I took a
look at it, and the set screw is cracked right down the side. When I
try to turn the screw the crack widens up and the wrench pops around
inside the hole. Its not a big deal I guess. These tool holders only
sell for around $50 used, but hey. $50 is $50.

Any suggestions. I have considered trying to tap in an oversized hex
key, but its right there. I have a drawer full but I haven't found that
one that feels like it almost wants to fit.