Why jewellery castings fail and how CAD can prevent it

By Ronak Rawal · 1 October 2026 · 2 min read

When a casting fails, the cause is not always the casting process. Often the model made it harder. Casters can share their own advice, but these are the common causes.

Thin sections

Metal may not fill very thin areas, leaving gaps or breaks. Keep walls and prongs above the minimum thickness your caster recommends. See the checklist.

Sudden changes in thickness

Thick areas cool slowly, and thin areas cool fast. Large differences can lead to pores or shrinkage. Where possible, keep thickness changes gradual.

Trapped gas and porosity

Gas can get trapped in the mould, leaving tiny holes. Smooth shapes and sensible placement of the model on the tree help. This is mostly the caster's job, but the shape matters.

Sharp internal corners

Sharp inside corners can crack or fill poorly. Small rounded corners cast better.

Model errors

• Gaps or open surfaces
• Parts that should touch but do not
• Wrong scale

Prevent it

Work with your caster, check the model, and test one piece first. Our final model check helps catch problems early.