Hey there-
I use precision-ground stainless rods for my jumps rings and
chain making, and they work great. They (along with other
really cool stuff) are available at: Small Parts, Inc.
(800)220-4242 e-mail: smlparts@smallparts.com Web:
www.smallparts.com
Unfortunately, they don’t seem to stock a 9/16" diameter rod.
They have just about every other size, though.
Cheers,
Elizabeth