Casting stainless steel jewelry is usually a lost-wax investment casting process. The main steps are:
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1. Product design
The factory creates a 3D CAD model of the ring, pendant, bracelet component, etc. The design must account for:
- Wall thickness
- Shrinkage during casting
- Draft and difficult geometries
- Stone-setting areas
- Polishing allowance
2. Make the wax pattern
A wax injection mold is produced from the jewelry model. Molten wax is injected into the mold to create an exact wax replica of the jewelry.
For small production runs, 3D-printed castable patterns can also be used.
3. Assemble the wax tree
Multiple wax jewelry pieces are attached to a central wax sprue, forming a “tree.”
The sprue system is important because it determines how molten stainless steel will flow into each piece and how air and gases escape.
4. Investment / plaster molding
The wax tree is placed inside a steel flask. A special investment slurry is poured around it and allowed to harden.
The result is a heat-resistant ceramic mold containing the negative shape of the jewelry.
5. Dewaxing
The hardened mold is heated in an oven/autoclave.
The wax melts and is removed, leaving an empty cavity corresponding to the jewelry design.
This is why the process is called lost-wax casting.
6. Burnout and preheating
The ceramic mold is heated to a high temperature to:
- Remove remaining wax
- Burn out organic residues
- Strengthen the investment
- Preheat the mold before metal injection
7. Melt the stainless steel
Stainless steel—commonly grades such as 316L for jewelry—is melted in an induction or vacuum melting system.
Stainless steel requires considerably higher temperatures than silver or gold, so the furnace and casting equipment need to be designed for high-temperature alloys.
8. Cast the metal
The molten stainless steel is introduced into the ceramic mold.
Depending on the factory, this can use:
- Vacuum casting
- Centrifugal casting
- Pressure-assisted/vacuum-assisted casting
The metal fills the jewelry cavities and solidifies.
9. Break the investment
After cooling, the ceramic investment is mechanically removed.
The stainless-steel pieces remain attached to the central sprue.
10. Cut off the castings
Each jewelry piece is separated from the tree using a saw, cutting wheel, or similar equipment.
The remaining sprue marks must then be ground away.
11. Grinding and polishing
This is a major part of stainless-steel jewelry production.
Typical operations include:
Rough grinding → surface leveling → fine grinding → polishing → ultrasonic cleaning
The factory removes:
- Sprue marks
- Casting seams
- Small pits
- Surface irregularities
12. Secondary machining
Depending on the design, additional operations may be required:
- CNC machining
- Drilling
- Threading
- Laser engraving
- Stone-setting holes
- Cutting
- Welding/soldering of components
13. Surface finishing
The jewelry can then receive its final surface treatment, such as:
- Mirror polishing
- Brushing
- Sandblasting
- Matte finishing
- PVD gold plating
- PVD black
- Rose gold PVD
- Other decorative coatings
14. Quality inspection
The factory checks dimensions, surface quality, casting defects, color/coating consistency, and functionality.
For higher-quality stainless-steel jewelry, factories may specifically inspect for porosity, cracks, incomplete filling, shrinkage defects and polishing pits.
15. Cleaning and packaging
Finally, the pieces are thoroughly cleaned, dried, inspected again and packaged.
Simplified factory flow
3D design → Wax mold → Wax injection → Wax tree → Investment molding → Dewaxing → Burnout → Stainless-steel melting → Vacuum/centrifugal casting → Investment removal → Cutting → Grinding → Polishing → Machining/stone setting → PVD plating → Inspection → Packaging
One important point: casting stainless steel jewelry is substantially more demanding than casting silver or brass jewelry. The melting temperature, mold requirements, filling behavior and finishing requirements are all more demanding. This is why a factory that genuinely specializes in stainless-steel casting usually has dedicated melting/casting equipment rather than simply outsourcing the casting stage.
