Sourcing & RFQ guide
How to get an accurate casting quotation on the first try
A quotation is only as accurate as the enquiry behind it. Send a complete RFQ and the offers you get back are comparable line for line. Send a drawing and nothing else, and every supplier will guess differently — which is why the same part can come back at €8 and at €14 with both numbers technically correct for a different set of assumptions.
Key takeaways
- A casting price is built from assumptions, not from the drawing alone. Material, tolerance, finish, quantity and lead time each move the number, often by double digits.
- Send nine things: material and standard, 2D and 3D files, critical tolerances, surface finish, annual and batch quantity, target lead time, packaging and marking, Incoterms, and destination market.
- The most common omission is quantity breakdown. Total annual volume with no batch size forces the supplier to guess at setup and tooling amortisation.
- State what you will accept. If a process substitution, a different gating position or a small design change is allowed, say so — it is often where the cost comes out.
- Compare like for like. Check that each quotation states unit price, tooling, sample cost, lead time, payment terms, validity, and whether freight and tax are included.
First, the cause
Why quotes for the same drawing vary so much
A casting price is built from assumptions, not from the drawing alone. Change any one of them and the number moves.
Volume and batch size
Tooling is amortised over the volume you quote, and setup time is amortised over the batch. A supplier assuming 500 pcs/year and one assuming 20,000 pcs/year will price the same part very differently.
How much is machined
As-cast and fully machined are two different products. If the RFQ does not say which faces are functional, some suppliers quote a raw casting and others quote a finished, inspected part.
Standards and documentation
Material certificates, radiography, third-party inspection and traceability all add cost. A quote with no documentation scope is not cheaper — it is incomplete.
Incoterm and destination
EXW from the factory and DDP to your warehouse differ by freight, insurance, duty and handling. Comparing them as if they were the same number is a common and expensive mistake.
The RFQ
What to send, and why each item matters
The required items are the minimum for a quotation that will still be valid when you place the order. The optional items sharpen the price or widen your options.
| Information | Required / optional | Why the supplier needs it |
|---|---|---|
| Material and standard | Required | Grade decides melt cost, machinability and which specification the certificate is issued against — quote the grade exactly as it appears on your drawing. |
| Drawings — 2D and 3D | Required | The 2D drawing carries tolerances, notes and finishes; the 3D model defines geometry for tooling. Both together prevent interpretation errors. |
| Critical tolerances | Required | Identifies which dimensions must be machined and checked, and which can stay as-cast. |
| Surface finish and treatment | Required | Defines whether the quote covers surface treatment, which process is used, and the target Ra on machined faces. |
| Annual volume and batch size | Required | Sets how tooling is amortised and how setup time is spread. This is the single largest driver of unit price. |
| Target lead time and delivery date | Required | Determines whether normal scheduling is enough or a rush surcharge applies. |
| Packaging and shipping marks | Required | Standard export packing and custom VCI, foam separation or branded cartons carry different costs. |
| Trade terms and destination | Required | EXW, FOB, CIF or DDP changes what is included. Give the named port or delivery address. |
| Target market and compliance | Required | Determines whether CE, pressure-equipment or other market certificates and test regimes are needed. |
| Reference part or sample | Optional | A physical or measured reference removes ambiguity about appearance and function, and speeds up first-article approval. |
| Assembly relationships | Optional | Knowing how the part fits its neighbours tells the supplier which fits and clearances are genuinely critical. |
| Weight or size limit | Optional | If the part has to meet a weight ceiling in service, the supplier can flag where a design change would help. |
| Acceptable process alternatives | Optional | If you will accept sand casting, machining from solid or a design tweak, say so and you may get a cheaper or faster route. |
If any required item is genuinely unknown at RFQ stage, mark it as unknown rather than leaving it out. An assumption stated in writing can be challenged; a silent assumption cannot.
Watch out
Omissions that void a quote
These are the gaps that turn a firm price into a revised one the moment you place the order — or into a quote that is quietly for a different product.
- No volume stated. The supplier picks one, and it is rarely the one you meant.
- No indication of which faces are machined. You may be quoted a raw casting when you need a finished part.
- Tolerances only on the 3D model. STEP files carry geometry, not GD&T. Send a toleranced 2D drawing.
- No Incoterm or destination. Two quotes cannot be compared, and neither can be turned into a landed cost.
- Finish or treatment mentioned in an email but not the RFQ. It will be missing from the price.
- No documentation scope. Material certificate, dimensional report and NDT are priced items, not free extras.
- A revised drawing sent without a version number. Suppliers end up quoting different revisions of the same part.
- No target date. You cannot tell whether the lead time offered actually meets your launch plan.
Files
CAD formats and confidentiality
Send both a 3D model and a 2D drawing. The model defines the geometry the tool is cut from; the drawing defines the tolerances, notes and finishes the model cannot carry.
| Format | What to use it for |
|---|---|
| STEP (.step / .stp) | Preferred 3D format — a neutral solid model read by any CAD system. |
| IGES | Older neutral format; accepted, but STEP is more reliable for solids. |
| DWG / DXF | 2D drawings with dimensions, tolerances and notes. |
| Fine for reading, but not suitable for tooling — always include a vector format as well. |
On confidentiality: an NDA costs nothing and removes the main reason buyers hesitate to send drawings overseas. If you do not have an NDA in place yet, send a watermarked 2D drawing for the initial price and hold back the 3D model until the agreement is signed. We sign and return NDAs before drawings are released, and drawings are handled only by the engineering and tooling staff who need them.
Compare fairly
What a quotation should contain
When offers come back, check that each one carries every field below. A missing field is not a saving; it is a cost waiting to appear on a revised quote.
Money
Price lines
- Unit price, with the volume it applies to
- Tooling cost, quoted separately
- Sample charge, and whether it is deducted from the first order
- Whether the price includes tax and freight
- Price validity period and the currency
Delivery
Time and terms
- Sample lead time from order
- Production lead time from sample approval
- Incoterm and named port or delivery point
- Payment terms (for example T/T or L/C at sight)
- Minimum order quantity for the quoted price
Scope
What is included
- Material grade and the standard certified against
- Which surfaces are machined and to what tolerance
- Finish and treatment included
- Inspection and documentation scope
- Packaging and marking included
Use our RFQ template
A one-page RFQ form covering every required field above, so your enquiry comes back comparable the first time. We will send it as an editable file.
Send a complete RFQ and get a firm price back
Use the checklist above, or just send what you have. You will get a written quotation with the price lines, lead time and terms spelled out against the drawing — not a range that changes when you order.