Why Jewelry Castings Fail: 7 Problems Designers Can Avoid Before Uploading a File

In jewelry casting, most failures don’t happen in the metal — they happen long before the pour.
Weak geometry, improper supports, porosity-prone areas, and incorrect wall thicknesses all originate in CAD. The casting house can’t fix those mistakes once the model is printed.

Here are the seven most common reasons castings fail, and what designers can do to prevent them before uploading a file.


1. Walls That Are Too Thin

The number-one failure point. Anything below 0.7 mm becomes fragile in printing and casting, especially in gold.

Designer fix:
Use 0.8–1.0 mm as a true minimum for bands, walls, and gallery structures.


2. Improper Supports (or No Supports)

Unsupported prongs, floating elements, and details hanging in mid-air lead to broken prints and incomplete castings.

Designer fix:
Add organic supports or ensure the print orientation makes sense — don’t rely on the caster to fix the CAD.


3. Overly Sharp Edges

Perfectly sharp edges don’t cast clean; they ball up or soften.

Designer fix:
Add micro-fillets or 0.1–0.2 mm softening to keep geometry clean after casting and polishing.


4. Incorrect Clearance for Stones

Seats modeled too tight cause stones to sit high or crack the metal when setting.

Designer fix:
Leave proper tolerance based on stone size and metal choice.
For most pavé and melee, 0.1–0.2 mm is ideal.


5. Thick-to-Thin Transitions

Sudden changes in mass cause porosity, sinking, or incomplete fills.

Designer fix:
Transition gradually — avoid “bulky” areas next to delicate ones.


6. Hollow Areas Without Escape Holes

A hollow model with no vents traps investment and metal.

Designer fix:
Add 1–1.5 mm escape holes in hidden locations.


7. Modeling With “Perfect” Geometry Instead of Castable Geometry

Designers sometimes model like product renderings — sharp, precise, zero-tolerance — not like objects meant to be poured in molten metal.

Designer fix:
Think like a caster:

  • keep geometry friendly
  • avoid razor-thin areas
  • round stress points
  • allow for cleanup after polishing

Final Word: Clean Files Cast Cleanly

Casting doesn’t forgive CAD mistakes.
A clean file means a clean print, a clean mold, and a clean final cast — with no surprises.

If you want perfect results, start with castable geometry.


Ready to cast your design?

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