On Oct 8, 6:29*pm, John Doe wrote:
Something thin to put between two pieces of 1/8" thick 1 1/2" wide
aluminum flat bar that are bolted together. A bearing that will
allow the two pieces of aluminum flat bar to be held firmly together
but move (the only way possible) against the spacer between them
with as little friction as possible.
...
Thanks.

How tight is the bolt, and what keeps it from loosening?