How Jewelry Casting Works: A Simple Guide for Designers

In jewelry manufacturing, casting is the step that turns your 3D model into a solid, workable metal part. Designers often understand CAD, measurements, and client revisions — but the foundry side can feel distant. This guide explains the casting process in simple terms so you know exactly what happens once your file is ready.

1. From CAD to Print

Every casting begins with a physical model. Most designers create this using CAD, which is then converted to:

• Wax prints (traditional)
• Resin prints (most common today)

What matters most is that the model is:

• Watertight
• Correctly scaled
• Has proper thickness
• Free of non-manifold geometry

A clean file produces a clean print. A clean print produces a clean casting.

2. Spruing and Trees

Once the model is printed, it’s attached to a sprue — a channel that allows molten metal to flow into the piece.

For production runs, multiple sprued models are assembled into a casting tree.
For single pieces, a designer may only have one or two sprues on a small base.

Good spruing reduces:

• Air pockets
• Porosity
• Shrinkage defects
• Metal turbulence

This step heavily influences final cast quality.

3. Investment and Burnout

The sprued model is placed into a metal flask and filled with a plaster-like investment material. Once it hardens, the flask undergoes a high-temperature burnout cycle.

During burnout:

• The resin/wax melts out
• The investment cures
• A clean cavity remains in the shape of your model

Proper burnout prevents surface texture issues and ensures metal fills evenly.

4. Casting the Metal

After burnout, the flask is brought to casting temperature and placed into a casting machine. Jewelers typically use:

• Centrifugal casting machines
• Vacuum-assisted casting systems

The chosen metal — gold, silver, or platinum — is melted and forced into the empty cavity inside the flask.

Factors that affect the final result:

• Correct metal temperature
• Proper flask temperature
• Oxygen control
• Pour timing
• Machine calibration

Clean metal flow produces smoother, denser castings.

5. Quench, Breakout, and Cleanup

Once the metal solidifies, the hot flask is quenched in water. The investment dissolves, revealing the raw cast piece.

The process then moves into:

• Removing sprues
• Trimming excess material
• Filing contact points
• Checking thickness
• Verifying stone seats (if applicable)

At this stage, you have a raw metal part ready for finishing, stone setting, or polishing.

Why This Matters for Designers

Understanding casting helps you:

• Design models that cast cleanly
• Avoid unnecessary revisions
• Reduce porosity and surface issues
• Set correct thicknesses for metal flow
• Improve consistency across production runs

A small change at the CAD stage can prevent major casting problems later.

Ready to Cast Your Design?

If your file is ready, you can upload it directly and see it in 3D with instant pricing.