Hello. I am wondering if there is a way to close stainless steel jump
rings made from 3/32 wire rod with a machine or possibly a device that
could be built. The jump rings diameter measure 1/2, 3/8, 1/4 and
5/16. I have been doing them by hand with two pliers and my wrists are
slowly wearing out. I used to close soft steel rings by pounding them
on a steel plate with no problem but I do not want to mar the surface
of the stainless. Any recommendations would be appreciated. Thanks.

Sounds like you are making chainmail, my advice would be to do a
couple of searches on how they make those , although when i tried all
i found is that they use 2 pliers like you to close the rings

Hi Fire,

I believe that I am about to do the same repetitive task in the
construction of wire-mesh cages to house a multitude of rabbits. You
can purchase a pair of pliers which have a longitudinal channel on
both gripping surfaces. This will place and hold the wire easily on a
vertical axis. Much easier on your wrists.

I do not recall the correct name of the pliers, but they should be
available to you at any rural hardware outlet. A short term fix might
be to file the channel yourself, 90 degrees to the ridge grips of your
pliers.

Regards, Phil