In brief
Start with an identified drawing revision, material requirement, order quantity and the features that need inspection. Separate the part definition from delivery, documentation and assembly requests so that suppliers can quote the same scope.
1. Send one consistent part definition
Identify the part number and revision on the drawing, model and RFQ list. If the 3D model and 2D drawing differ, identify which document governs each requirement instead of leaving the supplier to choose. State the drawing units and flag any dimensions that are still provisional.
Use the model for geometry and the drawing for requirements such as tolerances, threads, surface condition and inspection notes. Where a drawing requirement differs from the model, identify the governing requirement in the RFQ.
- Part number, drawing revision and units
- Readable drawing and available model with matching revisions
- Critical dimensions, datums, threads and sealing surfaces marked
- Open questions listed separately from released requirements
References: Protolabs: CNC Machining Services
2. Define material and delivered condition
Use the material designation required by your design and name the governing specification where applicable. A description such as brass is not enough to decide an alloy. If an equivalent grade may be proposed, say who must approve it and what evidence is needed before substitution.
List finishes, cleaning, protective packaging and documentation as requested deliverables. If the part serves a regulated application, identify the requirement and the evidence you need; a request for a certificate is not proof that a supplier holds that certification.
- Material grade and specification, or an explicitly unresolved selection
- Finish and surfaces that must remain untreated
- Material traceability or test documentation requested
- Medium and service conditions for engineering review, without treating them as an approved rating
3. Separate quantities and supply scope
Distinguish a sample request, the first production order and the expected repeat demand. Give separate quantities when you want comparable price breaks. State a requested delivery date and destination, while leaving feasibility and delivery terms to the quotation.
For a fitting or valve component, state whether you need only the machined body or also seals, nuts, cores or assembly work. An assembly photograph can explain the application, but it does not define which items are included in the price.
| Input | What to make explicit |
|---|---|
| Drawing | Part number, revision and governing document |
| Quantity | Samples, first order and repeat quantity separately |
| Supply scope | Body only, additional parts or an assembly to review |
| Inspection | Features, method, acceptance criteria and records |
| Delivery | Requested date, destination and packing requirements |
4. Agree on inspection before comparing prices
Mark which characteristics require an inspection record. Separate dimensional checks, material documents, cleanliness checks and any proposed leak or pressure testing. Each test needs its own agreed method and acceptance criteria; a dimensionally acceptable body is not automatically a validated pressure assembly.
If you do not know a value, label it as a question. For example, ask the supplier to identify what drawing detail is missing to quote a cross-hole edge inspection. Avoid filling gaps with assumed limits simply to make the RFQ appear complete.
- Are quote exclusions and assumptions visible?
- Does the inspection scope refer to the same drawing revision?
- Are one-time and recurring costs identified separately if applicable?
- Has responsibility for mating parts and final assembly tests been stated?
Sources & scope
Source pages checked on 2026-09-24. Publisher summaries and manufacturer references help identify the subject; they do not replace the specified standard or a reviewed part drawing. The checklists are editorial guidance for quotation preparation. External suppliers’ capabilities and certifications are not BOREVIA claims.
- Protolabs: CNC Machining Services
Example of model- and drawing-based manufacturing inputs. Supplier-specific tolerances and capabilities do not apply to BOREVIA.
From preparation to a defined RFQ
Bring the drawing and the open questions
State the part revision, material, quantity and inspection requirements. Pricing and feasibility need a review of the actual request.
Request an engineering quote