Originally Posted by
Dan Burkhart
I have a vague memory of Sheldon writing about securing a bottle cage to a steel frame with sheet metal screws. If I remember right, he thought it was an OK solution, but I don't think I'd want to try it.
It would probably work for a while, but some bad roads with a full bottle would eventually tear it out. OTOH, that hole is smaller than what the rivenut calls for, so you still have the option.