While flaring the first side of a spinner ring, the band split
nearly 1/3 of the way through. I don't believe that it was
overworked but haven't had this issue before.
Most likely, the split was at the joint or seam, be it a solder seam
or weld of some sort. Simply put, your solder seam wasn't strong
enough. Getting a solder seam strong enough to withstand this type of
stretching is not always simple.
Usually, doing this needs a seamless tube, or a seam that's been
welded, and then annealed, and then forged or worked, and annealed
again so that it ends up with no metalurgical differences at the seam
in the structure of the metal. Highly ductile metals, such as high
karat gold, work best for this sort of work. Stiffer alloys will need
considerable care to get it to work every time, since in general,
solder seams and welds start out not as strong as the original
You can easily demonstrate with with a ring stretcher to enlarge a
ring. Almost always, if there is an existing solder/sizing seam in a
wedding band, and you try to stretch it, the seams usually break
unless they've been done with unusual care to get maximum strength.