Tumbling a lobster clasp, depending on the media, may not be such a
great idea. Think in terms of grit in the mechanism wearing at
moving parts. Also consider water getting on the spring and rusting
it. I really don’t know, just thinking out loud (electronically that
is).
As for the rod, drill rod works well, old broken tipped screwdrivers
of differing diameters, drill bits, brazing rod from a welders
supply house…There are lots of sources of metal rod all around
you. We live in a throw-away society and, as the wise person said,
one man’s trash is another man’s treasure. (I am also quite
convinced that it works for women in exactly the same way.) There’s
rod all over the place, just about everywhere you look.
Have fun!
Mike