Gem Set Hinged Ring

I loved the idea of the hinged ring so much that I just had to do a fancier version in silver.

Gem set hinges was my first idea and then I realised that this was my excuse to buy something I'd wanted for ages: a tap & die set.
This would let me make stone set screw in fastening.

I selected a nice piece of watermelon tourmaline for the fastening (it's irregular shape would make turning it easier).  And matching green & pink tourmaline cabs for the hinge.

The finished piece was a bit of a disaster.  I think it LOOKS great, but the hinge is quite wobbly and the screw thread doesn't hold well (I don't know if I used the wrong combination of tap & die in the first place, or have stripped the thread during buffing & polishing).

The safety chain has also been troublesome.  It can't be soldered to the screw because it would just get tangled round & round.  So I attached the chain to a tag with a hole bigger than the screw thread, allowing it to spin freely.
The problem is how to keep this tag attached to the screw.  I attempted this by clamping a small washer shape around the screw thread.  It doesn't really work.