On Fri, 13 Sep 2013 06:43:22 -0700 (PDT), wrote:

If you can thread the hole it goes into you could thread some rod, stop and leave part unthreaded (the 'head'), screw it until the unthreaded portion jams to hold it in place.

This is probably going to be the winning idea. Had avoided in my mind
anything involving threaded holes since these are going in 1/4" thick
aluminum. Can easily make a few for a test run and back them up with an
external nut.

Also make them from cheap stock bolts.

Thanks all! Will post an update in a month or two after my mold runs
again.
--
William