Dear Mary, I am not 100% sure that we are talking about the same
thing,but “hand swedging Pliers” are used by Musical instrument
repairmen. You can obtain a set from Feree’s Tools. They are
heavy jawed pliers with grooves in the jaws. They are meant to
"stretch" and lengthen the tubes on sax, clarinet , flute and
other woodwinds that actuate the pads and keys.
I don’t have a number or website, but either a call to
1-800-info or a search on the web should turn up what you need.