A clear RFQ helps a CNC machining supplier understand what you need and review the part more efficiently. Providing a 3D model, a dimensioned drawing, and complete project requirements can reduce uncertainty during quotation and production planning.
1. Provide a 3D CAD Model
A 3D CAD model communicates the part’s overall shape and features. A neutral exchange format such as STEP is commonly used to share product geometry between different CAD systems. Autodesk describes STEP as a standard for exchanging product manufacturing data.
If your design includes multiple components, identify each part clearly. Make sure the submitted model matches the latest drawing revision.
2. Include a Dimensioned Technical Drawing
A 3D model may show geometry, but it may not communicate every manufacturing requirement. A technical drawing can specify:
- Overall dimensions and feature locations
- Required tolerances
- Thread sizes and specifications
- Surface finish requirements
- Critical dimensions or functional relationships
- Part number and revision
Clearly identify the dimensions that matter most for assembly or function. This helps the supplier focus the manufacturing review and inspection plan on the requirements that affect the part’s use.
3. Specify Material and Surface Finish
Write the material grade on the drawing or RFQ when it is known. If the material is not yet selected, explain the required strength, weight, corrosion resistance, temperature range, or other operating conditions.
Also specify any required surface treatment, such as anodizing, plating, polishing, or another finish. If no secondary finish is needed, state that the part will remain as machined.
4. Confirm Quantity and Delivery Requirements
Include the quantity for each part number and whether the order is for a prototype, a small batch, or production. If you expect repeat orders, mention that in the RFQ.
Provide a target delivery date or required lead time. The supplier can then review material availability, production requirements, finishing, inspection, and shipping together.
5. Identify Inspection and Documentation Needs
If the project requires a dimensional inspection report, material certificate, first article inspection, or other quality documents, list them before quotation. Document availability should be confirmed for the specific project.
CNC Machining RFQ Checklist
Before sending your files, check that you have included:
- 3D CAD model
- Dimensioned drawing in PDF or another agreed format
- Material and surface finish
- Quantity for each part
- Critical dimensions and tolerances
- Required inspection documents
- Drawing revision and target delivery date
If the files contain confidential design information, ask about an NDA before sharing them. OSM can sign an NDA when required before an RFQ.
Frequently Asked Questions
Is a 3D CAD model enough for a CNC quote?
It can help the supplier review geometry, but a dimensioned drawing and written requirements provide important details about tolerances, threads, material, and finish.
What if I do not know which material to choose?
Describe how the part will be used and the conditions it will face. The supplier can review possible materials with you.
Can I send an updated drawing after quotation?
Yes, but clearly identify the new revision. Design changes may affect the quotation, production plan, or delivery schedule.
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