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Palladium alloys
for jewelry manufacturing contain 95% palladium and 5% other metals.
Specific jewelry manufacturing methods like casting, machining, chain
making, hand fabricating or other processes sometimes call for differing
alloy ingredients. Of the popular alloys currently being used in the
U.S. for palladium jewelry the common balance consists of 95% palladium,
nearly 5% ruthenium and trace elements of other metals. The inclusion
of specific trace elements offer certain benefits to the manufacturing
process (e.g. hardness, better fluidity for casting, ease in machining)
or lend to better wear of the finished jewelry. Alloys containing 95%
palladium share inherent characteristics of the pure metal, such as - Malleability
- palladium is readily capable of being shaped or formed by hammering
or pressure.
- Ductility - palladium is capable of being drawn or bent without
breaking.
- Hardness - palladium has an as-cast Vickers hardness between
110 and 150 depending upon the alloy. With this hardness range, it
is relatively resistant to denting, scratching or bending and wears
similarly to platinum.
- Strength - with adequate tolerances, palladium has good strength
and will hold shape and form through strain or stress.
Well designed 950 palladium jewelry plays to the strengths of this
unique metal--the aesthetics of its light, bright, white color, weight
(comparable to 14k gold) and 'feel' as well as palladium's metallurgical
assets in setting, fabricating, casting and machining. It's a joy to
create a beautiful piece of jewelry which delights the wearer, and
promises to remain trouble free for years to come. So here's a tip:
Emphasize the positive qualities of this unique metal in your designs.
Whether palladium plays a supporting role to diamonds or fancy gemstones,
or takes the spotlight in visual form or tactile comfort, employing
its best characteristics in your creations will serve you well in saleable
jewelry, customer satisfaction and your bottom line.
This article examines 2 basic examples of 950 palladium jewelry. They
are both solitaires and both show examples of the best applications
of palladium's characteristics.
This example shows a comfort fit shank (inside of the
shank is slightly rounded) and a low profile 4-prong setting. The
inherent characteristics of palladium and the design of the parts
were considered in their selection as explained in the following
points:
The overall thickness of the shank is 1.85mm. This thickness
is required and offers the support necessary for the shank to hold
its shape through normal wear. Palladium's malleability, while desirable
in setting, would allow a thin shank to be easily deformed during
normal wear. Customers may be assured that the thicker shank is neither
bulky nor heavy, since the specific gravity of palladium is comparable
to (an equal mass of) 14 karat gold. The shank has a beveled design. The overall width is 4.10mm
and the flat portion at the top of the shank is 2.00mm wide. Palladium
has a desirable hardness for jewelry but is softer than the less
pure white gold alloys containing nickel. The narrow flat area at
the top of this shank will show less wear than a plain flat shank
with the same overall width of 4.10mm.
A
low profile setting was chosen with a total height of 5.65mm from
the base of the unit to the tops of the prongs prior to setting.
Taller profiles for this type of assembly are more vulnerable to
deformation such as twisting or bending. The
base of the setting measures 3.25mm offering a good amount of surface
area for soldering to the ring shank. Narrower widths would have
less contact and therefore be less stable and could bend and eventually
break during normal wear. The
prongs measure 1.00mm in width and 1.25mm at the prong top and
broaden to 1.90mm at the base of the prong. The tapering width
from bottom to top offers fantastic prong stability for normal
wear. Prongs of thinner dimensions when made in 950 palladium alloys
present a risk of becoming deformed during normal wear.
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When the mounting is assembled and set, the combined features of
this basic assembly provide a secure setting for the 6.0mm gemstone. |
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Important notes:
The contact area between the base of
the head and the shank measures 3.25mm (indicated by the red lines)
offering good strength and stability for the setting.
The prongs have sufficient length and thickness, providing
good security for the 6.0mm gemstone. |
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This example shows a half-round shank and a high profile 4-prong
setting. Again, these parts were chosen on the basis of palladium's
characteristic strengths and on the merit of their design for the
following reasons: The overall thickness of the shank tapers
from 3.60mm to 2.10mm at the bottom. This thickness offers support
for the shank to hold its shape through normal wear. The height
tapers from 2.50mm to 1.50mm at the bottom portion. Thinner shank
options would not be desirable as they could easily be deformed
during normal wear. The setting is high profile with a total height of 8.65mm
from the base of the unit to the tops of the prongs prior to setting
(3mm taller then the previous example). The prongs measure 1.00mm in width and 1.00mm at the prong
top and widen to 2.5mm at the base of the prong. The tapering width
from bottom to top offers great prong stability for normal wear.
Prongs of thinner dimensions when made in 950 palladium alloys
could present a risk of becoming deformed during normal wear.
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The method of assembly between this setting and shank differs from
the previous example. The top portion of the shank is cut so it precisely
interlocks between the prongs providing extra strength and security
to the assembly. |
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Important notes:
The height of the shank at the point
of assembly is 2.50mm. The width and interlocking feature of this
assembly provide ample contact area for added strength and security
to the high profile setting.
The high profile is balanced by proportionately thicker prongs
which widen at the base. This design feature greatly decreases
the chance of bending and deformation of the malleable palladium prongs
during normal wear. |
Be sure to use pre-made components (findings) that are designed and
made for palladium. Using dies originally designed for white gold to
strike out components for palladium could lead to problems. White gold
alloys contain high percentages of nickel and other metals that have
different metallurgical characteristics (e.g. low malleability and greater
hardness) than 95 percent pure palladium or platinum alloys. Dies designed
for white gold specifications may prove to be insufficient for use in
palladium jewelry components.
Watch this series of palladium jewelry manufacturing articles for more
on palladium jewelry design considerations.
Palladium Jewelry Manufacturing: Frequently Asked Questions:
When
palladium is used for jewelry manufacturing, is it as pure as platinum
or white gold for the same?
Palladium is a noble metal like platinum and from the platinum group
of metals. General purpose palladium alloys are typically mixed with ruthenium
(another member of the platinum group of metals, or PGM) and trace elements
of other metals. The content of palladium is 95% of the total alloy and
referred to as 950Pd. This means that 950 parts of 1,000 are palladium
and 50 parts are ruthenium and trace amounts of other metals. When white
gold is used for jewelry, it usually occurs as 14- or 18-karat. 14-karat
white gold contains only 58.5% gold in the alloy and 18-karat alloys contain
75% gold. Palladium and platinum are superior in purity over white gold
alloys. |
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