Oct 27, 2026CNC Machining Guides

CNC Machining RFQ Checklist: What Buyers Should Send for an Accurate Quote

A buyer-focused CNC machining RFQ checklist covering CAD, drawings, materials, tolerances, inspection, quantities, lead time, finishing, packaging and quote assumptions.

CNC Machining RFQ Checklist: What Buyers Should Send for an Accurate Quote

An accurate CNC machining quote depends on the information provided with the RFQ. When key requirements are missing, suppliers must either make assumptions or delay the quotation while asking questions.
This creates three common problems for buyers:
  • quotations that are difficult to compare
  • price and lead-time changes after order placement
  • avoidable manufacturing or inspection disputes
A strong RFQ does not need to be long. It needs to define the technical and commercial requirements that materially affect cost, quality and delivery.
Use this checklist to prepare a clearer CNC machining request for quotation and receive more comparable supplier responses.

1. Send Both the 3D Model and 2D Drawing

The 3D model defines part geometry and supports CAM programming. The 2D drawing communicates requirements that may not be fully defined in the model, including:
  • tolerances
  • datums and GD&T
  • surface finish
  • material
  • heat treatment
  • coating or plating
  • threads
  • marking
  • inspection notes
  • cosmetic requirements
Make sure both files show the same revision. If the drawing and model conflict, state which one controls and highlight the conflict before quotation.
Useful file formats may include STEP or Parasolid for 3D geometry and PDF for the controlled drawing. If native CAD is necessary, identify the software and version.

2. Use Clear Revision Control

A supplier cannot quote reliably when several file versions are included without explanation.
Your RFQ should identify:
  • part number
  • part name
  • drawing revision
  • CAD revision
  • RFQ revision
  • date issued
  • list of changed requirements
Use consistent filenames and remove obsolete files from the package. If the design is still changing, say which features are frozen and which may be revised.
For repeat orders, do not assume the supplier will recognize a new file automatically. Reference the previous purchase order and clearly state whether the revision changed.

3. Specify Material Completely

Material description affects availability, machinability, certification and finishing.
Include:
  • alloy or grade
  • temper or condition
  • applicable material standard
  • hardness requirement, if relevant
  • source restrictions, if applicable
  • certificate requirements
  • acceptable alternatives
For plastics, define grade, color, reinforcement and any special stability or compliance requirement. For metals, do not use a broad description such as “aluminum” or “stainless steel” when the grade affects function.
If alternatives are acceptable, ask the supplier to quote them separately rather than allowing an unapproved substitution.
See our CNC machining materials selection guide for common selection factors.4. Identify Critical Tolerances and Datums
A general tolerance note may not tell the supplier which features are most important to the assembly.
Mark or list:
  • critical-to-function dimensions
  • mating diameters and fits
  • sealing surfaces
  • bearing locations
  • true-position requirements
  • flatness and parallelism controls
  • datum relationships
  • inspection alignment requirements
Avoid applying unnecessarily tight tolerances to every dimension. If a tolerance is negotiable, identify it so the supplier can offer a manufacturing alternative.
For complex GD&T, explain the functional intent when possible. A short note about how the part locates in the assembly can help the supplier plan machining and inspection correctly.

5. Define Threads, Holes and Edge Conditions

Thread and hole requirements often create quotation questions. State:
  • thread standard and class
  • through or blind
  • required full thread depth
  • insert type, if any
  • hole tolerance or fit
  • countersink or counterbore dimensions
  • whether thread gauges are required
For edges, define whether you need a general deburr, controlled chamfer, radius or sharp edge. Avoid “break all edges” if certain sealing, locating or cosmetic edges require different treatment.

6. Specify Surface Finish and Cosmetic Standards

Do not rely on a generic note such as “good finish.” Define:
  • required roughness and where it applies
  • visible cosmetic surfaces
  • permitted tool marks
  • scratch and dent limits
  • grain direction, if relevant
  • sample or visual standard
  • handling requirements
If a surface will later be coated or hidden, make sure the as-machined finish is not stricter than the function requires.

7. Define Heat Treatment and Secondary Finishing

Secondary processes can strongly affect cost, tolerance and lead time.
For anodizing, plating, passivation, heat treatment, painting or other finishing, specify:
  • process type
  • applicable standard
  • thickness or class
  • color and gloss
  • masking areas
  • post-treatment dimensions
  • testing or certificate requirements
  • approved processor restrictions
State whether drawing dimensions apply before or after finishing. If threaded holes, fits or contact surfaces require masking, identify them clearly.
Our anodizing guide explains how coating buildup and masking affect machined parts.

8. State Quantities and Demand Scenarios

One quantity does not show how the program may develop.
When possible, request prices for:
  • prototype quantity
  • pilot batch
  • routine production batch
  • higher-volume scenario
  • estimated annual usage
Ask the supplier to separate one-time charges from recurring costs. This helps buyers see which programming, tooling, fixture or first-article charges should not repeat.
If demand is uncertain, say so. A realistic range is more useful than a large forecast that is unlikely to become an order.

9. Define the Inspection Package

Inspection requirements should be included before quotation, not added after the price is agreed.
Clarify whether you need:
  • first article inspection
  • ballooned drawing
  • dimensional report
  • CMM report
  • material certificate
  • heat-treatment or finish certificate
  • capability data
  • gauge results
  • sampling plan
  • photographs
  • retained samples
Identify which characteristics need reported values and which can be controlled by normal production inspection. If 100% inspection is required, state which dimensions or features are included.
Read our CNC machining inspection guide for more detail on FAI, CMM reports and sampling.10. Give a Real Delivery Requirement
“ASAP” does not provide enough information for capacity planning.
Include:
  • required delivery date
  • destination
  • partial shipment requirements
  • prototype approval timing
  • launch or assembly date
  • whether early delivery is acceptable
  • preferred shipping method
Ask the supplier to show both manufacturing lead time and estimated shipment timing. Confirm whether quoted lead time begins at RFQ, purchase order, deposit, material receipt or drawing approval.
If your schedule has flexibility, request a standard lead time and an expedited option separately.

11. Include Packaging, Marking and Cleanliness

Packaging can affect both price and delivered quality.
Define:
  • quantity per bag, tray or carton
  • protection against part-to-part contact
  • corrosion protection
  • protection for cosmetic surfaces
  • cleanliness or oil restrictions
  • labels and lot identification
  • part marking or serialization
  • export packaging needs
Parts that pass inspection can still fail at receiving if they arrive scratched, corroded, mixed or contaminated.

12. Explain the Part’s Application Without Revealing Unnecessary IP

Functional context can help the supplier identify risks and propose better manufacturing options.
Useful context may include:
  • mating features
  • assembly method
  • loading direction
  • sealing function
  • cosmetic visibility
  • operating environment
  • expected wear
  • critical failure mode
You do not need to reveal the full product design. Share enough information for the supplier to understand why certain requirements matter.
If confidentiality is important, establish appropriate controls before sending sensitive files. See our guide to protecting CAD files and IP.

13. Request Assumptions, Exceptions and Alternatives

Ask every supplier to list:
  • assumptions used in the quote
  • drawing requirements not included
  • proposed deviations
  • material or process alternatives
  • subcontracted processes
  • one-time charges
  • validity period
  • payment assumptions
  • tooling ownership
  • packaging assumptions
This makes quotes easier to compare. Two prices may look similar while covering different inspection, finishing or packaging scopes.
Use our CNC machining quote comparison guide to compare total supply risk rather than unit price alone.

Buyer’s CNC Machining RFQ Checklist

Before sending the RFQ, confirm that you included:
  • part number and current revision
  • 3D CAD model
  • controlled 2D drawing
  • material grade and condition
  • heat treatment and finishing
  • tolerances and critical characteristics
  • threads, holes and edge requirements
  • surface roughness and cosmetic standards
  • quantity breaks and annual usage
  • target delivery date and destination
  • first article and inspection requirements
  • certificate requirements
  • marking, cleanliness and packaging
  • approved alternatives
  • confidentiality requirements
  • request for assumptions and exclusions

Questions to Ask With the RFQ

Ask the supplier:
  • Which requirements are the main cost drivers?
  • Which details are unclear or conflicting?
  • What design changes could reduce cost without affecting function?
  • Which material or finishing risks could affect lead time?
  • What is included in the inspection package?
  • Which processes will be subcontracted?
  • What will change on a repeat order?
  • Which charges are one-time?
  • What information is still required before production?

Final Takeaway

A complete CNC machining RFQ helps buyers receive faster, more accurate and more comparable quotations. It also reduces the chance of price changes, delayed approvals and quality disagreements after purchase order placement.
To request a machining review, send Zync Precision your 3D model, 2D drawing, material, finish, quantities, inspection expectations and target delivery date. Clear requirements allow the supplier to identify risks early and prepare a more reliable quotation.