This may not help you, and I may not be visualizing your bezel quite
right, but I would typically cast a bezel like that. First of all,
please forgive me if this is explaining something you already know.
If you have a lathe you can turn it to get it as close as can, then
carve the rest. Or if no lathe or mill is available, carve a wax.
I would cut a piece off of a wax ring tube (flat top) as wide as the
wide st point of the bezel you need and ream it out to the correct
finger size to get the right curvature at the base of the bezel. All
you need this wax for is the bezel so you don’t care about the rest
of the shank, it just makes it easier to hold on to.
-Mark the height of the bezel with a scribe and trim the wax to
-Mark the center of the top flat with intersecting scribed lines.
-Drill a hole at the center of the flat top where the lines
intersect. (You need to work from the inside out on bezels, really on
-Use a cone bur or bud bur to remove almost enough material that
your 18 mm stone will nearly fall in the hole (hole should be under
18 mm at the top edge).
-Take a setting bur that’s a hair under the diameter of your stone
and cut a seat that is at the desired depth.
-Lay your stone over the hole and put your wax pen on the table,
Heat the stone (pen should not be glowing red) until it melts into
the seat and rests at the desired depth.
-Let it cool a little bit and push the stone out from the underside
with a toothpick. You now have a perfect seat for your stone.
-Trim the inside of the bezel at the seat with a ball bur so you
don’t have an excessively large seat touching the pavilion. If you
don’t do this it will goof you up when you go it set it. You really
want a minimal seat, enough to hold it but not too much too much to
push the stone out of position.
-Make sure the rest of the inside of the bezel is just how you want
it, the hole at the base is centered and the right size, the walls
taper evenly, etc.
-Now that the inside of the bezel is all ready you can begin to file
and shape the outside of the bezel so it looks just how you want it
-When it’s ready you just cut it off the shank and cast it.
-After you finish it and solder it in place, setting it is much
easier because you already created the seat for the particular
stone. It won’t fit right in the seat because of a little shrinkage
and because the bezel will no longer flex.
- If it were me setting it I would probably trim the opening just a
bit with the vertical edge of a setting bur to make it so the stone
just almost fits in the opening and so the inside edge of the bezel
is perfectly round.
-I’d then clean up the seat with a 70 or 90 degree hart bur
(depending on the angles of the stone).
-If needed I’d lift a portion of the bezel lip a hair by running the
tip of a round nose pliers around the inside of the seat, just enough
to lay the stone in place.
-If seated properly I’d then knock down the bezel with a hammer
This has to be done carefully and would take another few paragraphs
to explain…so if you’re not accustomed to that tool use a burnisher
or whatever you’re comfortable with. If you are using a hammer
handpiece it’s as important to shape the bezel as it is to tighten
Sorry this was so long. It is so much harder to write this stuff down
that to just show someone how to do it. Anyway, hope it helps.