Introduction
A complete CNC RFQ gives a manufacturing partner the information needed to evaluate feasibility and prepare a useful quotation. Missing material grades, unclear revisions or incomplete finish requirements can lead to follow-up questions, quotation delays and incorrect assumptions.
The goal is not to create the longest possible request. It is to provide the right technical, commercial and delivery information in a clear package.
1. Provide a controlled 2D drawing
The 2D drawing is usually the primary reference for dimensions and requirements. Include:
- Part number and drawing title
- Revision and issue date
- Units and projection method
- All functional dimensions
- General tolerances
- Datums and geometric tolerances where required
- Material and temper
- Surface finish and treatment notes
- Quantity or drawing reference to the RFQ
Avoid sending an outdated drawing together with a newer CAD model without explaining which file controls. Identify the current revision clearly.
2. Add the 3D CAD model
A 3D model helps the manufacturing team understand complex geometry, pockets, holes, radii and assembly interfaces. Common formats can include STEP or another neutral format accepted by the supplier.
The model should match the drawing revision. If the model is for reference only, label it that way. If there are differences between the model and drawing, resolve them before requesting a final quotation.
3. Specify the material precisely
Write the exact material grade and, where relevant, temper or condition. Examples may include 6061 or 7075 aluminium, 45 steel or SK2 steel. A broad description such as “aluminium” or “steel” may not be enough for pricing or process selection.
If you are open to alternatives, describe the functional requirement and ask the supplier to list any proposed substitution separately. Do not let a substitution become an unrecorded assumption.
4. State quantity and production stage
Quantity affects setup, programming, material purchasing, inspection and unit price. Include:
- Prototype quantity
- Sample quantity
- Initial production quantity
- Expected repeat quantity, if known
- Annual demand or forecast, if relevant
If the project is moving from prototype to production, say so. The best process for one prototype may not be the best process for repeat production.
5. Identify critical tolerances
Mark the dimensions that control fit, alignment, sealing, motion or assembly. Explain the functional reason when possible. Do not apply a very tight tolerance to every dimension unless the design requires it.
A tolerance depends on machine capability, material, geometry, process method and inspection method. A manufacturing partner should review tight requirements against the complete drawing before confirming feasibility.
6. Explain surface finish and post-processing
State the required finish and the purpose behind it. For example:
- Anodizing for appearance, protection or wear resistance
- Powder coating or painting for a specified environment
- Polishing for appearance or surface condition
- Heat treatment for mechanical requirements
- Deburring and edge-break requirements
Include color, thickness, masking areas, cosmetic standards and dimensional limits where relevant. Finishing can affect dimensions, fit and final appearance, so it should be part of the quotation review.
7. Define inspection requirements
Tell the supplier which features need verification and what documents are expected. Requirements may include an inspection report, material certificate, first-article records or photographs, depending on the project.
Before production, confirm:
- Critical inspection features
- Datum references
- Measurement method
- Acceptance criteria
- Report format
- Responsibility for final approval
Do not assume a certification or inspection capability until it has been confirmed for the selected manufacturing partner.
8. Include delivery and commercial information
A useful RFQ also states:
- Delivery destination and preferred shipping method
- Required delivery date or target lead time
- Packaging requirements
- Incoterm or export responsibility, if already defined
- Currency and quotation basis
- Whether tooling, programming or inspection costs should be itemized
If a commercial point is not decided, label it as an open question instead of leaving the supplier to guess.
9. Use a clear file package
Use descriptive filenames and keep related files together. A simple package might contain:
Part-123_Rev-B_Drawing.pdfPart-123_Rev-B_Model.stepPart-123_Finish-Requirements.pdfRFQ-Notes.txt
Remove obsolete revisions from the submission folder or clearly mark them as reference only.
CNC RFQ checklist
Before sending, confirm that you have:
- Current 2D drawing
- Matching 3D CAD model
- Material grade and temper
- Quantity and production stage
- Critical tolerances and datums
- Surface finish and post-processing
- Inspection and documentation requirements
- Delivery destination and timing
- Commercial questions and assumptions
- A named contact for technical clarification
How ExactMach handles an RFQ
ExactMach coordinates suitable manufacturing partners for custom machined parts. The enquiry is reviewed for drawing completeness, material, process, tolerance, finish, inspection and delivery information. Questions and assumptions are identified before feasibility, price and lead time are confirmed for the individual project.
FAQ
Can I request a quote with only a 3D model?
A 3D model may support an initial estimate, but a controlled 2D drawing is normally needed for dimensions, tolerances, datums, material, finish and inspection requirements.
What if my drawing is not finished?
You can request an early engineering discussion. Clearly mark the drawing as preliminary and list the requirements that are still changing.
How quickly can an RFQ be quoted?
Timing depends on drawing complexity, quantity, material, finish, inspection requirements and how complete the information is. A complete file package reduces avoidable clarification cycles.
Request an RFQ review
Send your drawing package, quantity, material and delivery destination for a project-specific review.