Back to Ganoksin | FAQ | Contact

Wall thickness for tube setting a stone


hi all

i want to set a stone in a tube setting can anyone advise me on what
sort of wall thicknees i should go for when i buy the tube? i was
goin to cut the tube with a setting bur now another question is when
i come to set the stone how deep should the stone sit under the edge
of the tube, i hope i explained what i mean because this is the
first time i have attempted to do this

many thanks


In general terms, I usually consider about.5mm to be a starting point
for bezel wall thickness, at least for 14 and 18k alloys. 22k is
easier to form, and deform, so I usually increase the thickness. You
can always file or otherwise remove some metal.The depth is
determined by the thickness of the girdle of a faceted stone, or the
curvature of a cab. The metal does need to hold the stone without
hiding much of it. It really is proportional to the size of the
stone, and to a degree how much wear the setting is likely to get.
Go look at what is out there, bezel settings have been successfully
made for thousands of years.

Rick Hamilton

what sort of wall thicknees i should go for when i buy the tube? how
deep should the stone sit under the edge of the tube 

How long is a piece of string? There are many variables which will
determine the answers to your questions. What is the diameter of the
stone? A 2mm stone will require a thinner wall than a 10mm stone,
for example. I either make my own tube settings from 0.5mm sheet (so
0.5mm walls) or thicker homemade sheet, or I sometimes buy tubing
for smaller stones. The tubing I buy is 4mm outside diameter and 3mm
inside diameter so it comes with 0.5mm walls but they are reduced
when the seat is cut. I set 3.4mm stones into them so they end up
with approximately 0.3mm thickness walls. As for how deep the stone
sits under the edge of the tube - it depends on how thick the stone’s
girdle is. If it’s a thick girdle, you’ll need a deeper seat cut in
the tube. Personally, I measure and eyeball the height needed above
the seat using a steel ruler. Hold the side of the stone against a
steel ruler with the girdle (bottom of the girdle) adjacent to a
major measuring mark on the ruler. Judge how much metal you want to
fold over the stone and that will tell you how many mm you need from
the top of the tube. I’m sure there are more accurate methods but
it’s never failed me yet.



Jason, A thicker wall is going to give you some fudge factor,
which’ll be handy if this is your first attempt. If you use a setting
bur your thickness will be theoretical, nominal at best since its
tricky to have that thingie run absolutely true and concentric. As
far as depth…when your seat is cut and you plop the stone in place
there should be enough wall height to allow for the metal to fold
over and get some purchase on the crown without obscuring more than a
minimal amount of the crown facets.

I would suggest that after you think you have the seat just right,
go back in with a suitably sized bud or flame bur and narrow up the
actual seat from inside. This reduces the tendency for the stone to
rest on the pavilion facets rather than as close as possible to the
girdle. You’ll get a steadier seat. Steadier is easier to set and the
stone will be brighter. If after you cut with the flame bur the stone
now sits a little low merely dress off the bezel top with a file.

For small stones I’d like to have .3-.4mm thickness. larger stones up
to .7mm, roughly. For depth its really hard to give a figure, you
have to eye ball it.


Just a little note, I prefer again to use correct names for the
facets of the stone…such as Crown, Star and Kite facets…here is my
reasoning…I prefer to have the metal of the tube setting not to
exceed the Crown facet…these little facets are the ones just above
the girdle…plus no metal should ever be above and encrouching upon
the “Kite” facet…this is my rule of thumb on any form of
setting…such as claw/prong or even bead-setting…enough for now.

hope that this is a help to you all…gerry!


Dear all

One of my first new videos I will be making is just on tube setting.
Let me first explain one thing IN PRINT, the finished height of the
"table of the stone" to the tube wall must be that the “table” and
wall must be the same height… This is after filing and cleaning.
Why? you will run into premature wearing of the gold and expecting
loss of the stone…I personally like to have some metal over the
table height, just to avoid this problem.

So where does this leave you? Kindly make a seat about 1/3 the depth
from the top—>to the base of your tube…or putting it another way,
drop it down enough that you have enough working depth/metal. This is
to allow for much of your aggressive preparation.

Do not make any beads inside any wall…this is the failing shortcut
many of the setters use…this is not the correct way to set any form
of tube setting…:>( So what happens if you don’t have a decent sharp
graver at your ready? Not set the stone?..duh?

Has anyone mentioned using a “hart” shaped bur or commonly called a
"156C" bur…the bur must not be the same size as the girdle
diameter. The size of bur should not exceed 75% the size of the
stone…period!!! Make bur cuts all around the inner tube/wall all
at the same tube-depth and into the wall, also at the same inner cut.
Do not exceed any cutting that will weaken the tube wall. If you make
a deep cut, you will do two things…totaly weaken the wall structure
and have great problems in getting the stone tight…this is like
overkilling the cutting process…again, don’t use beads.

Trim some of the outside wall to to prepare the pushing over of the
metal…I use a # 4 Triangular cut 20 cm. file and make incremental
filing all around the tube…then you can use a brass pushing
tools…not steel…as this might leave marks on the metal and you will
have much grief getting those marks off of the outer wall and then
weaken the nicely prepared tube wall.

I would prefer to just use a fine finishing process using a flat
edge/surface, pumice wheel of only 180 grit strength to do your
cleaning…remembering you are involved in a very thin wall. Make
sure all of the wall IS OVER THE STONE, check with your 10x loupe
all through the setting procedure.

If you folks can wait till I make one of many videos you will have
all of the answers necessary. If you would like to assist me, kindly
write to me and tell me what topics you would like to view in great
detail…" viewing is lots better, than reading"… Gerry!