For generations, New York City’s Diamond District has been the center of fine jewelry production in the United States. Within a few blocks on 47th Street, jewelers, designers, and retailers collaborate with specialized trade shops to bring creations to life.
Among all the steps in the manufacturing process, casting remains one of the most crucial. Casting transforms a design - whether drawn on paper, modeled in CAD, or scanned from an existing piece - into a precious metal form ready for finishing.
At Tech-Designs NY, we specialize in casting services for professional jewelers and retailers. This guide explains the complete casting process, common pitfalls to avoid, and why working with a local Diamond District partner ensures your projects meet the highest standards.
What Is Jewelry Casting?
Jewelry casting is the process of transforming a model into a finished piece of metal. In modern manufacturing, this typically follows a file-to-cast workflow:
- CAD Design or 3D Scan - a digital model is created or captured.
- 3D Printing – the model is printed in high-resolution resin or wax.
- Investment & Burnout - the model is encased in plaster-like investment, then burned out to leave a cavity.
- Metal Casting - molten platinum, gold, or silver is poured into the mold.
- Finishing - polishing, stone setting, rhodium plating, and QC bring the piece to completion.
Every stage requires precision. A weak CAD file, a flawed print, or poor casting technique can compromise the final product.
The Role of CAD in Modern Casting
Before a single gram of metal is poured, the CAD file determines success. A clean, well-prepared digital file saves jewelers time, money, and frustration.
Common issues we see with CAD files include:
- Missing or incomplete geometry (gaps, overlaps).
- Incorrect stone dimensions or missing seats.
- Overly thin prongs or walls that break during polishing.
- Files exported in low-resolution or incompatible formats.
At Tech-Designs NY, we recommend jewelers always submit CAD files in .3dm or .stl formats and ensure the model is watertight. For stone setting, precise seat depth and prong alignment are essential.
👉 Related reading: 5 Mistakes Jewelers Make with CAD Files (and How to Avoid Them)
3D Printing: From File to Wax
Once the CAD file is approved, the next step is 3D printing. Using high-resolution resin printers, we create ultra-smooth models that form the basis for casting.
Benefits of 3D printing for jewelers:
- Accuracy: prints capture micro-details like pavé layouts and filigree.
- Surface quality: smooth prints reduce polishing time.
- Prototyping: designers can test size, scale, and fit before committing to precious metal.
- Speed: in NYC’s Diamond District, file-to-print can happen within hours.
For trade jewelers, the ability to move quickly from design to print is a competitive advantage.
👉 Related reading: 3D Printing for Jewelers: From Prototype to Production
Choosing the Right Metal: Platinum vs. Gold
The choice of casting metal affects not only the appearance of the piece but also the complexity of the process.
Platinum Casting
Platinum is the most demanding of all jewelry metals. It melts at approximately 3,200°F, requiring advanced equipment and expert handling.
Challenges of platinum casting:
- Higher risk of porosity if not cast properly.
- Susceptible to shrinkage cracks in delicate areas.
- Requires specialized alloys for strength and brightness.
Despite these challenges, platinum remains unmatched for durability and prestige. In NYC, clients often expect platinum for engagement rings and high-end designs.
Gold Casting (14K vs. 18K)
Gold offers more flexibility but requires careful alloying.
- 14K Gold: Durable, affordable, excellent for everyday wear.
- 18K Gold: Richer color, higher purity, softer but more luxurious.
Casting 14K vs. 18K gold requires adjustments in temperature and investment. Jewelers should choose based on the final client’s needs - durability vs. luxury.
Finishing: Where Jewelry Comes Alive
Casting creates the skeleton of a piece. Finishing is where it becomes a sale-ready jewel.
Professional finishing includes:
- Polishing: removing rough surfaces for mirror shine.
- Stone setting: secure mounting of diamonds and colored stones.
- Rhodium plating: brightening white gold to a crisp finish.
- Final inspection: ensuring every detail meets client standards.
Many jewelers attempt finishing in-house but quickly discover the time and skill required. Outsourcing to a dedicated bench team in the Diamond District ensures consistent results.
Why Local Casting in NYC Matters
In today’s global economy, it’s tempting to outsource casting overseas. But for trade jewelers, local manufacturing in the Diamond District offers clear advantages:
- Speed: File-to-cast in 2 business days - sometimes faster.
- Direct communication: Drop off, pick up, or meet in person.
- Confidentiality: Submissions protected under NDAs.
- Community support: Partnering with local shops sustains NYC’s jewelry trade.
For jewelers working on tight deadlines, nothing replaces the speed and trust of a local partner.
FAQs About Jewelry Casting
Q: How long does casting take?
A: Most jobs are completed within 2–3 business days. Rush services are available.
Q: Do you accept single-piece jobs?
A: Yes. We handle everything from one-off projects to large production runs.
Q: What metals do you cast?
A: Platinum, 14K & 18K gold (yellow, white, rose), and sterling silver.
Q: Do you sign NDAs?
A: Yes. Every file submission is protected under our Non-Disclosure Agreement.
Conclusion
Jewelry casting is both a science and an art. From CAD file preparation to metal selection and final polish, every step determines whether a design will succeed in the real world.
By partnering with a trusted Diamond District casting shop, jewelers gain more than just a vendor. They gain a collaborator who understands the pressures of the trade, the expectations of clients, and the importance of precision.
At Tech-Designs NY, we help jewelers, designers, and retailers move seamlessly from file to finished piece. Whether you’re working in platinum, gold, or silver, our team is here to ensure your designs are cast with accuracy, speed, and care.
👉 Ready to start your next casting project?
Upload your CAD file today for a platinum or gold casting quote.
Or call us at (212) 354-7575 to discuss your next project.
🛠️ About Tech-Designs NY
Located in the heart of NYC’s Diamond District, Tech-Designs NY LLC specializes in full-service jewelry manufacturing — from CAD design and 3D printing to casting, finishing, and laser engraving.
We proudly serve jewelers, designers, and retailers who demand precision, reliability, and expert craftsmanship.
🚀 Ready to Start Your Next Project?
Bring your design or CAD file — we’ll help you turn it into a flawless finished piece.
📩 Upload your CAD file →
📍 Visit us: 37 W. 47th St, 15th Floor – New York, NY
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💎 Related Reading
- The Complete Guide to Jewelry Casting in NYC
- Inside Our Platinum Casting Process
- 3D Printing for Jewelers: From Prototype to Production
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