Platinum Alloys for Jewelry

Platinum 95% Ruthenium 5%

950 Platinum Ruthenium (950PtRu) is the most widely used platinum jewelry alloy in the United States. With a hardness of 130 Vickers, it is malleable enough for easy setting but strong enough to stand up to daily wear. Its natural white color is nearly identical to platinum-iridium alloys often seen in antique jewelry and should be considered over PtIr for matching a customers existing piece.  In addition, for long term wear, PtRu is superior to white gold with a similar coloring for those customers who want white.

Pro Tip: 950PtRu has a greater tendency to form internal porosity during casting over other alloys.  But this is easily healed through our Hot Isostatic Pressing (HIP) process that not only improves internal porosity but saves time on the bench through denser and more uniform microstructure in the metal .

Platinum 95% Cobalt 5%

950 Platinum Cobalt (950PtCo) is unmatched for filling fine cross-sections and design details such as filigree or latticework. PtCo has the greatest molten flow capability of any platinum jewelry alloy on the market; it flows at a lower temperature and can fill fine details better than PtRu. Also being platinum, it has a good hardness of 135 Vickers and good wear resistance. It should be noted that Platinum Cobalt has a slight blue hue compared to 950PtRu.

Pro Tip: 950PtCo is slightly magnetic and oxidizes when exposed to heat. While this might be troubling on the bench the oxidation is easily removed. 950PtCo is often preferred for its ability to cast fine designs and polish more quickly.

Platinum 95% Ruthenium-Gallium- 5%

950 Platinum Hard Cast (950PtHCA) is a harder jewelry alloy that offers extra protection against wear and distortion. The 5% Ruthenium-Gallium offers superior hardness at 180 Vickers. It has a natural white color nearly identical to 950PtRu and is perfect for the customer who is hard on their jewelry.

Pro Tip: 950PtHCA is excellent for hard-on-jewelry customers who tend to abuse their rings. This jewelry alloy has lower molten flow capability so extra care is required in design to fill thin or delicate areas, not all designs are a good choice for this alloy so call us to talk about your design needs.

Platinum 90% Iridium 10%

Widely used for years in both casting and fabrication, 900PtIr and 950PtIr have been demonstrated to be too soft for jewelry applications when used purely in cast form.  Both anecdotal and scientific research confirm this fact, so we actively encourage jewelers to switch to one of our other jewelry  alloys.  TechForm has participated in multiple research papers and you can read the research on wear resistance .

Gold Alloys for Jewelry

14k Vivid Yellow Gold – Au 58.5% / Cu 28.47% / Ag 7.18% / Zn 5.81%

The 14K Yellow Gold “Vivid” alloy delivers a bright, vibrant yellow tone with outstanding strength and wear resistance. Ideal for everyday jewelry and high-volume production, this alloy combines beauty with durability. 14k Yellow Gold 0106

18k Rich Yellow Gold – Au 75.2% / Ag 12.6% / Cu 11.4% / Zn 0.82%

This premium 18K yellow gold alloy offers a deep, luxurious color and excellent casting performance. Known for its rich tone and durability, it’s ideal for fine jewelry applications where beauty and strength matter. 18k Rich Yellow Gold Alloy 0112 

18k Royal Yellow Gold – Au 75.2% / Cu 6.7% / Ag 16.5% / Zn 1.6%

Stuller’s 18K Yellow Gold “Royal” alloy offers a slightly lighter, elegant hue compared to traditional yellow gold, making it perfect for designs that call for a refined, sophisticated look. 18k Royal Yellow Gold 0115

More Jewelry Alloys to Explore- Stainless Steel

316L Stainless Steel  is the workhorse alloy for the jewelry industry’s steel needs. It comprises approximately 60% iron, 18% chromium, and 14% nickel, with small percentages of molybdenum, manganese, and others. Even though 316L has 14% nickel, it is still considered among the most biocompatible of the stainless series. It has been used in the medical industry for heart stents and spinal implants. Nevertheless, it is important to be aware of the risk for nickel sensitivity when using this as a jewelry alloy. This is particularly true for piercing designs where, ironically, it is the most popular.

Other benefits of 316L are its rust resistance and malleability—both key factors for jewelry use. Stones can be set with relative ease, and rust is better inhibited by the specific combination of elements used in 316L compared to other stainless steels.

We highly recommend Hot Isostatic Pressing for all steel castings.  The HIP process eliminates shrinkage, which can be a problem with stainless steel castings.

Stainless steel is priced in two ways, either by a full or partial flask as follows:

• Full Flask:  For this option, we will fit as many pieces of your jewelry designs as reasonably possible into a 5 ½” x 7” flask.  Conservatively, 9 to 12 large men’s bands will fit in a flask, but it will depend on the size of your project.
• Partial Flask:  With this option, you share your flask with another customer and pay only for the portion of the flask that you consume.  The turnaround time on a partial flask option is longer as we wait for enough orders to fill the flask.  You can call to ask if we have a flask waiting to be filled or for the current turnaround time.
• Minimum Charge: There is a $125.00 minimum charge for partial flask orders of stainless steel jewelry castings. For example, one men’s band would cost $125, and two would be $250. This pricing does not apply to large pieces such as bangle bracelets or other designs that consume large portions of the flask. In this case, it’s best to call and discuss your project’s individual needs.

For pricing on full or partial flasks, please call 503-652-5224 or email info@techformcasting.com , and we will be happy to advise you.

Cobalt-chrome as a Jewelry Alloy

Cobalt-chrome, a unique alloy composed of approximately 67% Cobalt, 27% Chromium, and 6% Molybdenum, stands out in the metals industry for its exceptional wear resistance. This makes it the metal of choice for artificial joints, demonstrating its high biocompatibility and suitability for certain jewelry applications.

While Cobalt-Chrome has an incredible luster after high polish, it has certain limitations among the jewelry alloys. The high level of wear resistance also causes it to resist tools, making it very difficult to drill holes, set stones, or size in a traditional manner. The best use for this metal can, therefore, be found in pendants, earrings, cufflinks, necklaces, bracelets, etc., that do not require sizing and for designs that showcase the metal versus stones. Stones, when needed, can be riveted or glued in place. Another benefit of cobalt chrome is its susceptibility to blackening. Blackening is done through a chemical process that creates a black oxide layer providing a wonderful contrast with platinum, palladium, and gold alloys. The blackening process itself is not widely published; however, many jewelers have devised their own methods for the durable blackening of this metal.

We highly recommend Hot Isostatic Pressing for all cobalt chrome castings.  The HIP process eliminates shrinkage, which can be a problem with this alloy.

When it comes to Cobalt Chrome casting, we offer two pricing options for your convenience. You can choose between a full or partial flask, each with its own unique benefits and considerations.

• Full Flask:  For this option, we will fit as many pieces of your jewelry designs as reasonably possible into a 5 ½” x 7” flask.  Conservatively, 9 to 12 large men’s bands will fit in a flask, but it will depend on the size of your project.
• Partial Flask:  With this option, you share your flask with another customer and pay only for the portion of the flask that you consume.  The turnaround time on a partial flask option is longer as we wait for enough orders to fill the flask.  You can call to ask if we have a flask waiting to be filled or for the current turnaround time.
• Minimum Charge: There is a $125.00 minimum charge for partial flask orders. For example, one men’s band would cost $125, and two would be $250. This pricing does not apply to large pieces such as bangle bracelets or other designs that consume large portions of the flask. In this case, it’s best to call and discuss your project’s individual needs.

For pricing on full or partial flasks, please call 503-652-5224 or email info@techformcasting.com , and we will be happy to advise you.