On Sun, 18 Aug 2019 17:35:54 -0700 (PDT), AK
wrote:



The opening in the hex screw that holds the rear brake cable has become much looser than it used to be. What is the name of the part so I can order another one? (Hopefully they have some made of harder steel.)

https://imgur.com/a/JT76Qog

It is simply a clamp bolt and the question is whether it holds the
brake cable tightly when it is tightened, If it does than I shouldn't
worry about it.

As the bolt should be clamping the cable between a flange or washer on
the bolt and the brake arm itself. When it is tightened it shouldn't
move at all.

Your picture looks a bit strange, but maybe it is the perspective. See
https://sheldonbrown.com/canti-direct.htmlto
from a slightly different angle.
--

Cheers,

John B.