What to send a foundry for an OEM casting quote
A foundry can price a part in two days or two weeks. The difference is almost never the foundry. It is whether the enquiry arrived complete.
The five things that stop a quote
1. Material grade. “Cast iron” is not a grade. QT450-10, QT500-7, HT250 or KTH330-08 each behave differently and are priced differently. If the part must weld, say so — that changes the grade.
2. Machining allowance. A casting drawing and a machined drawing are not the same document. If you are buying a machined part, mark which faces are machined and how much stock you expect.
3. Tolerances that matter. Give a general tolerance block and then flag the two or three dimensions that actually control assembly. Everything at ±0.05 mm means the part costs three times what it should.
4. Volume. First order and annual demand, separately. A foundry prices tooling against the annual figure and the piece price against the run length.
5. Destination. Country and port. Packing, pallet standard and documents differ, and they are part of the price.
What to attach
- 3D model (STEP or IGES) for the pattern and the machining program.
- 2D drawing (PDF) with datums, critical dimensions, thread callouts and surface finish.
- Standard to inspect against — ISO 8062 for casting tolerances, or the one your customer names.
- Any test you need: material certificate, hardness, NDT, pressure test, dimensional report. Ask for them at quotation stage, not at shipment.
What the foundry will ask back
| Tooling | Pattern and core box, priced separately and usually owned by the customer |
| Sample lead time | Typical T1 sample 3–5 weeks after drawing approval |
| Machining | Whether it is done in-house or subcontracted — this changes lead time, not just price |
| Minimum run | Below a certain quantity, tooling dominates the price |
| Surface | As-cast, shot-blasted, primed, painted, galvanised |
Five mistakes that cost a week each
- Sending a PDF of a 3D model instead of the model.
- No datum scheme, so nobody can tell which face is the reference.
- Wall thickness that cannot be cast without a core — this needs a design conversation, not a quote.
- Asking for ±0.1 mm on an as-cast surface.
- Quoting a price from another factory and asking us to match it without the drawing.
What we send back
Within two working days you get a manufacturability review — whether the part suits our lines, where the casting risks are, what tooling it needs — and then tooling cost, sample date and piece price at your volume. If the part does not suit us, we say so, and tell you what kind of foundry it does suit.