Tumbling does work-harden sterling. Using steel shot (mixed shapes)
does a great job on earrings, jump rings, rings, wire work (ie, cuff
bracelets, etc), castings, and generally other pieces where the
majority of the pieces are not flat sheet. Large areas of flat sheet
need to be buffed out after tumbling in steel shot. It takes a
beating in the tumbler, literally, so there’s really no advantage
tumbling it over just buffing the piece.
Using a magnetic tumbler w/ the steel pins is great for very small,
angular pieces, ie, castings, where you need tiny areas polished. It
leaves a very tiny dimpled surface (better description would be a
polished sandblasted surface) all over what would normally would be
highly polished, so it is necessary in some cases to take to the
buffer after, for a quick buff.
My favorite tumbler is the “cement mixer” type. It’s model #250 from
It’s 3-way action is quite effective. My hand fits in the opening, so
I can if I wish, leave the lid off, dip my hand in, grab the piece(s)
to check, or toss in another piece while tumbling. No big lid thing
to deal with. We have two barrels: one, green for jewelry, and the
other black for rock tumbling (which never happens anymore because
I’ve basically taken it over from my lapidary husband.)
I like my vibratory tumbler, as well, but the cement mixer is my
fav. Disclaimer, love the product, but no affiliation w/ Covington.