An RFQ for castings should state the drawing, the material grade, the weight, the quantity, the tests and the delivery terms, so that every foundry quotes the same thing. A vague request gets vague replies that cannot be compared.
This article gives the checklist and then shows how to read the answers.
What should a casting RFQ include?
Send one package to every foundry. Include these items:
- Drawings or 3D models with dimensions, tolerances and machined faces marked.
- Material grade with the standard, for example grey iron, ductile iron, steel or stainless steel grade.
- Part weight, annual quantity and the size of the first order.
- Testing requirements: chemical analysis, mechanical tests, hardness, pressure test or non-destructive testing.
- Whether you want the casting rough or machined, and any heat treatment or surface finish.
- Packing, delivery term and destination port.
What about patterns and tooling?
Tell the foundry whether you will supply a pattern, or whether they must make it. Ask them to quote the pattern separately and to state who owns it. Pattern cost and ownership covers the points to settle.
Also state the process you expect, such as sand casting, shell moulding or investment casting, or let the foundry propose one and explain why.
How do you compare the replies?
Line the replies up in a table. For each, note the process, material, weight basis, tooling terms, test plan, lead time, payment terms and what is excluded. Differences in these often explain differences in the quote.
Check that each reply uses the same weight basis, whether rough or machined, as casting quotes are often built on weight. Look for exclusions such as machining, painting, packing and inspection. Comparing engineering quotes shows the method, and what to send for an engineering quote covers the RFQ pack in more detail.
Ask each foundry to state its yield assumptions and any allowance for scrap. A foundry that quotes a very low weight-based figure may be assuming an optimistic rejection rate, and the difference can return as delay or a request to renegotiate.
What are warning signs in a reply?
Be careful with a reply that is much lower than the rest and says nothing about material or testing. It may assume a cheaper grade or skip inspection.
Be careful with a reply that agrees to everything without questions. A good foundry will query tolerances, draft, section thickness or shrinkage. Ask for photographs of similar castings and of the testing equipment, and consider an audit before you place an order.
Keep a record of your questions and the answers. When a foundry says it can hold a tolerance or a pressure test, write that down as an agreed requirement and put it in the purchase order. It is much harder to enforce a verbal promise.
Finally, send your RFQ to enough foundries to see a spread, but not so many that you cannot review each properly. Three to five audited foundries is usually enough for a first project.
Next step
We prepare and send RFQs to audited foundries, compare the replies on a like-for-like basis, and supervise sampling and loading. To send your castings out for quote, book a free sourcing review.