Tube setting is
a simple method of setting that can take as little as five minutes or less
per setting given a specified stone size and a suitable tube to fit the
stone. The setting is visually clean, has a professional look to it and
can be done with a minimum of tools. Note that setting is usually done on
jewellery that is finished. Setting is then the last step in the process
of making the piece.
Process and procedural understanding Remember that this short descriptive paper can only be a guide as circumstance
and individual taste will vary the requirements of the piece. It is however
useful to have a generic starting point for dealing with technique. It
is the responsibility of the user to exercise their thinking to use the
information for maximum advantage. Ways of learning to think for technical
problem solving include always going to the Process in an attempt to understand
what is occurring with the metal. The Process is what really happens in
a procedure, what the material is experiencing in it's most basic terms,
of heat or pressure, or flow. With a tubing setting the process is easily
understood. Metal is removed from a tube to allow a facetted stone to
enter and be supported by the remaining uncut wall thickness of the tube.
The remaining metal of the tube wall that juts above the girdle of the
facetted stone as it sits on the ledge cut into the tube is then bent
and compressed in such a way as to flatten and flow inwards onto the tapering
sides of the stone effectively trapping it in place. Remember the decreased
circumference from the original outer diameter of the tube and the smaller
circumference of its final set position; the material flows into itself
to enable the reduction in circumference to occur. One should then imagine
all possible methods of attempting this metal removal and stone entrapment..
It is useful to have someone else handy to bounce ideas off in this type
of exercise, though many of us including myself often work on technical
solutions in isolation so one has to do it oneself. The methods that are
examined should be as wide ranging and even silly as possible as long
as they will work. In this case it could be anything from etching or scraping
or casting to using burrs. By listing them all even briefly mentally one
begins to develop an understanding of Process, of what is occurring in
a technical procedure. This in turn leads to faster solutions for the
technical problems that one experiences. Contrast and comparison of technical
procedures and options leads to a knowledge of the nature of the material
used and a freer approach to metal working. Craftsmanship is also enhanced
in this approach to working.
Suggested tools (see
- Set of round burrs - Wax cone for moving
- Set of setting burrs - Point burnisher
- Burnisher - Bezel pusher
- Bezel rocker - Stone leveling tool (ie:
a blunt toothpick)
- Pitch stick or other tool for keeping - Burr
- Setting rigid while setting - Safety goggles
(wear at all times)
- Flexible shaft with foot control
The setting procedure As it is easiest to use tube settings for round stones a round tube is
normally used. One can however use other shapes of tubing if one has the
appropriate stones. The recommended sizes of round stones for tube setting
have a diameter from 1mm to about 6mm. It should be noted that larger
sizes can be set in tubing if necessary. At a certain diameter size (above
8mm or so) engraving tools in a European engraved setting technique are
recommended. The suggested wall thicknesses depend to some extent upon
the size of the setting. In general for diameters below 5mm a wall thickness
of 0.5mm is sufficient. Very solid settings for stones with diameters
from 8 mm and over are made using a 1mm wall thickness. With the larger
sizes an even greater wall thickness is recommended. Standard seamless
tubing in silver and gold as well as brass from the hobby store can be
used for sizes under about 6mm diameter. These often have a wall thickness
of 0.3mm but seem to work well.
In the setting a seat for the stone is created within the tube by removing
metal from the inside of it to create a form fitting ledge for the stone
to sit upon. As a result the stone must be smaller in diameter than the
outside diameter of the tube but larger than the inside diameter of the
tube. As a rule when one places the stone on top of the tube and looks
straight down at it one can see one half of the wall thickness; the stone
covers the other half.
To cut the seat a choice of tools is available. The process is metal
removal from the inside of the tube. The seat opening is cut to the exact
same size as the diameter of the stone. One can precut the seat by placing
the tube in a chuck such as that of a flexible shaft handpiece and rotating
it against a burr or even a graver. For production of tube settings the
same thing is done using lathe tools and a lathe. The flex shaft can be
set up easily with hose clamps to fix the handpiece in place and allow
a burr to be held into the rotating tube to cut seats. A sawblade placed
upside down in the sawframe can then be used to slice off the completed
setting while it rotates against the sawblade teeth allowing one to make
seats and cut off several individual settings before having to reseat
the whole tube in the handpiece chuck. it is possible to precut a seat
and slice off a tube setting in this way in under 6 seconds per unit.
Bezels for calibrated stone sizes are often made this way with the seat
being precut before soldering in place on the piece. A straightforward uncut tube can be soldering to an object to create
a tube setting. One can remove the metal for the stone's seat by using
various tools. Each cutting tool will however be the same size (diameter)
as the stone. Best is to place the stone table down on a flat surface,
gently place the opening of one's vernier callipers over it and close
them gently on the stone. One then carefully removes the stone and passes
cutting tools through the gap in the jaws until the same size is found.
Both tool and stone will then have the same diameter. A choice for cutting
the seat, albeit a poor one is a drill bit. This is an emergency tool
as it has a tendency to bite into the metal and either drill too far into
the tube or jam and twist it. Better would be a standard setting burr
as is often used in North America. This however has the drawback of damaging
the walls of the setting severely if it is held the least bit tilted relative
to the tube. This can be difficult for even a practiced goldsmith to do
and therefore using setting burs often leads to poor quality tubing settings.
Setting burs like this also rapidly fill with metal or even burn if too
much metal removal at once is expected of them. Most professional setters
if using them will therefore first clear metal out using a ball or a bud
burr and follow up with the setting bur so it does not have to remove
much material, is not filled with metal and can be more easily controlled
as to what it is doing; that is which angle it is held at while cutting.
A setting burr should be run a a relatively low speed as high speed can
burn them quickly. Burning occurs when the burr discolors from the heat
of friction which tempers it so that it's cutting teeth dull quickly.
The use of a lubricant such as Burr Life ®, a light oil or a hard silicone
cross country ski wax can also increase the life of a burr. A note on
setting burrs is that it a the rare stone with the exact pavilion angle
of the setting burr and the resulting angle of the cut seat can create
undue pressure on part of the stone during setting causing damage to it.
My preference for tubing setting is to use a ball burr with a medium cut.
The main advantage is that it automatically stays centered in the tube
no matter what angle it is held into it. This allows much faster working
and quickly cuts the seat albeit with a curved profile.
The preferred steps in preparing
the setting would then be:
Tube with seat cut / Drill bit /Setting burr /Round burr
- Choose the tube so that wall thickness
and material strength are appropriate for the size of stone used (24k
gold or fine silver would be too soft). The suggested wall thickness is
from.0.8 mm to 0.4 mm. 0.5 mm is a good thickness for most settings. Place
the stone on the tube so that when looking straight down on it it covers
one half the wall thickness. Check to see that an suitable amount of wall
thickness is visible outside the stone to obtain a seat to support the
stone. It is suggested that at least 0.2mm be visible. Too much visible
means too much work to clear the seat and is resolved by a correct choice
of wall thickness for stone size.
- Choose a cutting tool to suit.
I recommend a round burr the same size as the stone. If it is smaller
than the stone it can be manually held against the wall of the tube and
run around to cut the seat. Ideal would be the same size as the stone.
Note that you can follow up by using a setting burr in the prepared seat
to make things crisp. Be aware of the danger of damaging the wall if you
tip the burr. I usually just use the round burr by itself in stone sizes
less than 4mm. The setting burr as a follow up may be advised for larger
- Cut the seat with the burr and
insert the stone to check for fit. This checking is done repeatedly. Goldsmiths
and setters check everything all the time and it is a good habit to develop
as it improves control and decision making tremendously. The girdle of
the stone should be about 0.5 mm below the top of the setting. One can
set it a little deeper or a little shallower but as a general guide 0.5
mm is a good starting point. If one cuts the seat too deep it is easily
brought to the correct depth with a few gentle strokes of a file. When
the correct depth is achieved, stop.
- Check that the stone is level by
placing it in it's setting so that a light source or white wall reflects
from the table of the stone to the eye. The table shows up brightly. Then
place one's thumb upside down over the setting so that the setting itself
is cast into shadow. The reflecting table facet will show up brightly
and can be used to judge for level relative to the setting. In a round
burred setting the stone will have a tendency to tip. The stone is leveled
either by removing it and replacing it with the wax cone or by pressing
on one part of the table with a tool, preferably wood or bone. I use small
brass leveling tools for this (see appendix).
- At this point the method of pushing
the wall over the stone to hold it in place is chosen. This could be a
burnisher, stone pusher, the side of the bench pin, a bezel rocker, a
setting punch or even a point burnisher. A production setter might use
a flex shaft hammer handpiece or a kind of a punch with a hemispherical
polished cup at the end which is struck onto the setting to close it over
the stone like a bezel rocker. A bezel rocker is an almost identical tool
with a polished concave hemispherical cup at it's end which is used to
set a round tubing setting by placing it over the setting and rocking
it. In all cases there is pressure against the part of the tube wall above
the girdle of the stone such that it is tapered inwards with sufficient
pressure and speed to close it tightly against the surface of the stone.
If the pressure is such that work hardening occurs without the metal moving
far enough then it may be very difficult to close the tube tightly upon
the stone as it will have a tendency to 'feather' or spring back from
it leaving a visible gap between the bezel wall and the stone. If this
occurs then one has to use a setting punch or extreme force to push the
metal downwards, in a new direction of pressure in order to tighten it
against the stone. The metal should be moved as far and as fast as possible
to prevent this work hardening occurring.
- The stone is set carefully with
much checking for level. One begins by applying pressure first on one
side of the bezel wall at about a 45o angle to the stone and then on the
side opposite until the stone is tight. A stone can be set with only two
opposite points bent over it but this is not adequate visually for a standard
tubing setting. The stone is set just as one might stretch a canvas, by
pressing the tube wall over the stone first north-south, then east-west,
then the remaining opposite points. Care is taken that the stone remains
level. Sometimes this requires bending part of the bezel wall over without
the stone in place, slipping the stone into position and then pushing
the side opposite to the initial bend over the stone to set it. Finally
it is burnished smoothly and tightly to the stone with a burnisher or
point burnisher. One uses the least pressure necessary to do the job to
avoid potential damage to the stone. As the metal must be moved as far
and fast as possible this is a judgement call on the part of the setter.
Experience is obviously an asset here. Most setters begin by practicing
with glass stones as if one can learn to set glass then one becomes relatively
sensitive to the stone being set. The material of the tube must be taken
into account with a 14k gold wall requiring more force to move than a
22k or a sterling wall. The least force is represented by a hand burnisher
or a point burnisher. Next would come a hand held pusher or bezel rocker
and then after that a punch or the rounded end of the chasing hammer (yes
that is one thing they are used for). If one uses the hammer then the
thumb is placed over the stone to protect it from any missed blow. Most
people prefer the safety of using a punch or a hand held pusher to the
- The material around the stone is
then burnished tight with some kind of a burnishing tool. The point burnisher
may be used to smooth the inside wall of the setting by holding it vertical
to the tube and sliding the rounded point around the inside wall against
the stone. Once more, pressure is minimal as one does not want to damage
- Sometimes a setter will clean
up the inside edge of a bezel type setting (usually in larger sizes) by
using a razor sharp very small flat engraving tool to trim the inside
edge of the bezel and round it out. It can happen that if less expensive
stones with large crown (top) facets are used that the setting appears
angular afterwards as the metal has been squashed down on the plane faces
of the stone. This tends to happen if the stone is set a little deep in
the tube or if the wall thickness bent over the stone is quite thin. In
this case one can use the small flat graver to produce the look of a round
setting by adjusting the visual thickness and curve of the bezel when
viewed from above. This is an example of something goldsmiths and setters
do at times which is to adjust the appearance of something visually to
make the viewer think it is round or otherwise more perfect than it is.
- The stone is now set and the setting
finished. Traditionally one might leave the setting without further polishing
with the marks of the setter's burnishing tools in place on the metal.
Usually one gives the marked metal a slight finishing with rouge, as tripoli
would remove the sharp crisp look left by the setter.
Descriptions of suggested tools:
Wax cone for moving stones around:
This tool is made by taking a lump of beeswax about the size of the
top joint of your index finger and kneading it between the fingers until
it becomes soft and pliable. It is then rolled in powdered charcoal (one
can file a charcoal block or drawing stick) and thoroughly kneaded to
mix it. One adds charcoal powder and kneads again. Occasionally one tries
to pick up a pair of pliers with the wax. When it will pick up the weight
of a pair of pliers and hold it for a count of ten then the mixture is
about right. The wax mixture is then shaped to a conical form and the
pointed end is used to pick up stones and manipulate them in their settings.
The wax cone will also remove a stone stuck in it's setting by working
it down upon the stone a suddenly jerking upwards with the wax. Even an
apparently impossibly stuck stone will come out eventually using this
Stone leveling tool :
This tool functions to produce a small area of pressure on a stone's
facet to level it in it's setting. It therefore must have a small end
to produce a restricted pressure point and be soft enough that it will
not scratch or damage the stone. Traditional materials for such a leveling
tool include wood, ivory, bone , copper and brass. A toothpick will work.
My favorite is a traditional tool made of a brass rod tapered on both
ends with a lentil-like boss in the middle which one presses against with
the fingers when using it. A diagram follows:
Wax cone and Brass Stone Leveling Tool
There are many shapes and materials for burnishers. The process is that
a harder, polished material is rubbed with or without a lubricant (it
is better with) against a softer material (the metal) giving it a similar
degree of polish to that of the burnisher. The burnisher described here
is a standard jeweller's or printmaker's burnisher. Usually one blunts
the end somewhat with a grinding wheel, emery papers and polishing buffs
to impart an end shaped like a thumb to the tool and to give it the highest
possible shine I like a compound called Fabuluster® for this. The burnisher
should be made out of hardened steel. Sometimes burnishers made of stones
like agate or haematite are used and these if well polished give a good
finish to metal. Burnishers are often used to highlight edges in jewellery,
to give a piece a 'frame' composed of very thin light streaks off the
edge itself. They refine details in stonesetting well such as the outside
off a bezel or the details of a prong setting by accentuating the edges
of all parts of the setting.
Printmaker's or jewellers burnisher
Point burnisher in handle
This tool is made by taking an old or broken burr and grinding the end
of it to a point. Care is taken not to overheat it while grinding and
thus cause the loss of the temper, which is ideal for a burnishing tool.
It is then rounded slightly.with emery papers and polished. this tool
can be mounted into a graver handle or held in a universal collet handle
such as is used for beading tools and millgrain wheels. Sometimes special
burnishing shapes are made from burrs and held in the handle. Most useful
however is a simple point burnisher.
Pushers come in various configurations, some for bezels and many for
other kinds of settings. There are about 18 different shapes in my box
of setting tools. One makes them to suit specific situations. Most useful
however is a rectangular cross sectioned rod set into a graver handle.
The rectangular end of the tool measures about 1.5 mm by 4 mm. This flat
end of the tool is hammered onto emery paper to give it a tooth so that
it grips and does not slip when it is in use. The tool should if possible
be hardened and tempered to a pale yellow so that it does not wear out
quickly. The shaft of the tool has it's edges beveled slightly so it is
comfortable in the fingers and the back end is set into a graver handle.
Like a graver the handle is tucked under the third finger in the palm
of the hand and the other fingers closed over it. The feeling of setting
the stone is a kind of squeezing of the graver handle forwards to press
the setting into place on the stone. One should lock one's legs around
the chair and brace one's shoulder when setting with a pusher. The whole
body is used to control the tool. Like a graver the handle is held very
hard in the hand in order to gain control of it.
Point Burnisher and Bezel pusher
This tool was described above and is essentially a rod with a cup-shaped
depression in the end into which the setting fits. A variety of sizes
are needed as one ideally has a rocker which fits the stone one third
of the way into the concave hemispherical cup. The cup is rocked north-south,
east-west and rotated to set the stone. The procedure is very fast and
is a clean setting method, especially for smaller stones. The tool may
be made by drilling into the center of a steel drill rod some 5 mm and
then going in with a round burr (which follows the drill shaft) to cut
the concave hemisphere. It is then polished using felt end buffs or a
piece of soft wood in the flexible shaft with some polishing compound.
Bezel rocker - Setting fits one third of the way into cup
Pitch stick or other tool for keeping setting
rigid while setting and placing pressure on the work.
This can be made from a six inch or longer length of broom handle. Pitch
or some other easily melted and adhesive substance is placed on the end
of it and used to fix a piece of jewellery or a setting in place in order
to allow easy setting. The piece may be heated slightly and pressed into
a prepared platform of pitch on the end of the pitch stick or the pitch
may be warmed slowly and kneaded back and forth on a smooth steel surface
to mix it and shape it to receive the object to be held. Never let the
pitch get runny! Fingers near pitch can be dipped in water to protect
them while shaping the pitch. (This is a hazardous procedure-Think!) The
setting or object is supported by the pitch so that one can hammer on
it or otherwise apply considerable force to the setting without the fear
of bending it out of shape. The purpose of the tool is also to fix the
setting in place on an axial handle (which is rotated in the notch in
one's bench pin) which allows easy use of gravers or other setting tools.
When it is time to remove the object if it is just stuck in the top of
the pitch it can be gently heated (remember thermal shock and stones do
not mix) and removed. Do not quench the setting. Any pitch residue can
be removed by soaking for a time in paint thinner or similar solvent.
Do not put porous stones like opals into such solvents. A cleaner method
is when the pitch is cracked off by sharp blows to it with a bench hammer.
If done correctly this leaves almost no pitch residue to remove.
In North America orange flake shellac is often used by setters but I
find it too brittle and hence dangerous to be of any real use. I remember
too a biologist shuddering that setters would be breathing heated shellac
fumes (pitch fumes too should be vented). Other materials like dopping
wax are also too brittle. If one is pressing hard on a setting with an
engraving tool and it gives way one can put a graver right through one's
hand-fairly unpleasant. I recommend black setter's pitch from Karl Fischer
GMBH in Pforzheim for this purpose. It is warmed with heat from a hair
dryer, heat gun or the part of the heat from a torch flame where you can
still hold your hand-not too hot. If the pitch bubbles and smokes it is
far too hot and is being damaged as well as becoming very runny and dangerous.
Wear goggles around pitch. Be aware of the burn hazard.