Sand Casting vs Shell (Croning) — When to Specify Which
2026-07-17
French federation listings frequently tag moulage sable à vert, chemically bonded sand and coquille / Croning. Those tags are a fast way to shortlist — but process choice should follow geometry, surface, dimensional class and annual volume, not directory fashion.
Green / chemically bonded sand
Use sand routes when:
- Geometry is bulky or core-heavy.
- Tooling cost must stay moderate for medium series.
- Surface and CT class are acceptable for machining stock.
Read more: sand castings handbook and browse process-tagged profiles via the directory hub.
Shell moulding / Croning / coquille
Specify shell-family processes when:
- Thinner walls and cleaner surfaces reduce machining minutes.
- Repeatability for medium–large series matters.
- Pattern/tooling investment is justified by volume.
Knowledge Centre: shell moulding handbook. Category filters on european foundries help you find listings that declare Croning/coquille language.
Decision table (practical)
| Driver | Lean sand | Lean shell/Croning |
|---|---|---|
| Prototype / low volume | Often better | Only if surface critical |
| Thin sections | Limited | Stronger fit |
| Heavy machining expected | Acceptable | May reduce stock |
| Tooling budget | Lower | Higher |
RFQ language that prevents ambiguity
Ask suppliers to state: mould/core process, typical CT class, surface reference, heat-treatment state and whether shell is used for the whole casting or only cores/skins.
CTA
Compare process tags in the directory, confirm theory in the Knowledge Centre, then send an RFQ that freezes the process family before tooling kick-off.