Developing a new casting, from drawing to approved samples, typically takes from several weeks for a simple sand casting to a few months for a complex or tested part. The time goes into pattern making, sample pouring, inspection, testing and your approval.
The biggest delays are rarely in the foundry itself. They come from unclear drawings, slow approvals and sample rounds that could have been avoided.
The main stages
- Drawing review, where the foundry checks the design for castability and proposes draft, fillets, machining allowance and parting line.
- Methoding, where gating, risers and cores are designed, sometimes with solidification simulation software.
- Pattern and core box making, in wood, resin or metal.
- Sample pouring, usually a small batch from a production melt.
- Fettling, heat treatment and, if ordered, machining of samples.
- Inspection and testing, including dimensions, chemistry, mechanical tests and any NDT.
- Your review and approval, or a request for changes.
What makes it longer
Some parts naturally take longer. Expect more time in these cases:
- The part has complex cores, thin walls or large thickness changes that need several methoding trials.
- The pattern is metal or the part needs shell moulding or investment casting tooling.
- Radiography, ultrasonic or pressure testing is required on samples.
- Machined samples are needed and the machining set-up must be developed too.
- The first samples fail and the pattern or method must be modified.
How to keep it short
Send a complete package: a 2D drawing with tolerances and material grade, a 3D model if you have one, annual volumes, and test requirements. The checklist in what to send for an engineering quote applies directly.
Agree the inspection plan before samples are poured, so the foundry knows what you will measure. Use a structured first article inspection on samples. Reply to questions and sample reports quickly, because each week of silence is a week lost.
Plan for at least one correction round on a complex part. It is better to build it into your schedule than to promise your customer a date that depends on perfect first samples.
After approval
Approval of samples is not the end. The first production batch should be inspected against the approved samples, because production moulds and melts can behave differently from a careful sample run. Keep a signed reference sample at both ends.
Record the approved pattern revision, method and process settings. If the foundry later changes the pattern, the gating or the sand system, it should tell you and resubmit samples. Uncontrolled changes after approval are one of the most common reasons good samples turn into poor production.
Next step
We manage the drawing review, chase samples, inspect first articles and supervise the first production batch. To plan a new casting, book a free sourcing review.