CNC Machining RFQ Checklist: What to Send for Faster, More Accurate Quotes

When you request a quote for precision CNC machining, the fastest way to get an accurate price and lead time isn’t “send less”, it’s send the right info the first time.

Below is a practical RFQ checklist we recommend for CNC turned, milled, and Swiss-machined parts. It reduces back-and-forth, prevents assumptions, and helps your supplier quote exactly what you need.

1) Send both the drawing and the 3D model (when available)

Best combo:

• 2D drawing (PDF) with dimensions, tolerances, notes, revision, and date

• 3D model (STEP preferred) to reduce interpretation risk

If your print and model conflict, your supplier has to stop and clarify, which adds time.

2) Confirm material, temper, and any compliance requirements

Material names like “aluminum” or “stainless” are too broad.

Include:

• Material grade + condition/temper (example: “6061-T651 plate” or “17-4PH H900”)

• Any compliance needs (RoHS/REACH, DFARS, domestic melt, etc.) if applicable

If you’re still deciding which material makes the most sense for the application, see our material selection guide for CNC machining.

For aluminum parts, this overview of common aluminum alloys for precision machining can help you choose the right grade and temper.

3) Define quantity and your “real” demand pattern

Your price will often change dramatically based on quantity and repeatability.

Include:

• This order qty

• Estimated annual usage (EAU) if it’s a repeat part

• Whether you want prototype pricing or production pricing

If you’re not sure what terms like tolerance, chip load, backlash, or interpolation mean, our CNC machining terms to know guide can help.

4) Call out critical dimensions and functional tolerances

Tight tolerances drive:

• More careful setups

• More inspection time

• Sometimes additional operations (finish passes, reaming, grinding, etc.)

Best practice:

• Use tight tolerances only where function requires it

• If certain features are critical, label them clearly (notes like “CTQ” or “critical to function” can help)

5) Specify threads clearly (and how you plan to verify them)

For threaded features, include:

• Thread standard (UNC/UNF, metric, NPT, etc.)

• Size, pitch, and class (e.g., 2B/3B as applicable)

• Depth requirements and any special notes (rolled vs cut, locking patch, etc.)

If thread verification matters, note whether you expect go/no-go gaging, CMM verification, or another method.

6) Surface finish, cosmetics, and edge requirements

This is a common “quote drift” area.

Include:

• Surface finish requirement (Ra) where it matters

• Cosmetic expectations (e.g., “no visible tool marks on face A”)

• Edge condition (deburr, edge break size, “no sharp edges,” etc.)

If you don’t define edge expectations, different shops may assume different standards.

Not sure what Ra means or how it’s measured? Here’s a helpful NIST surface finish metrology tutorial.

7) Any secondary operations (finishing, heat treat, marking, assembly)

List requirements like:

• Anodize, plating, passivation, powder coat

• Heat treat, stress relief, hardness requirements

• Laser marking / serialization

• Press-fit assembly, Loctite, packaging requirements

If a finish changes dimensions (common with coatings), it may affect tolerances, better to flag it early.

8) Inspection requirements and documentation

If you need special inspection, say so up front:

• First Article Inspection (FAI)

• Material certs (MTRs)

• Inspection reports (ballooned print, CMM report, etc.)

This impacts both lead time and price.

9) Target lead time and any scheduling constraints

Even if you’re flexible, tell your supplier what “success” looks like:

• Desired ship date

• Whether partial shipments are acceptable

• Any dock scheduling or packaging rules

Quick RFQ “copy/paste” template

If you want a super simple RFQ email structure, use this:

• Part name / part number:

• Revision:

• Quantity (now) + estimated annual usage:

• Material + temper/condition:

• Finish / secondary ops:

• Any critical dimensions/features:

• Inspection/doc requirements:

• Attachments: PDF drawing + STEP model

Let’s make quoting easy

At Machining Concepts, we prefer quoting from clean prints, clear callouts, and complete requirements — because it produces better pricing, fewer surprises, and faster delivery.

If you’d like a quote, send your print/model and RFQ details through our Request a Quote page, or email our salesperson, Jeff Duncan at JDuncan@machiningconceptserie.com

Related:

Essentials of CNC Machining: Material Selection (link)

The Most Common Aluminum Alloys for Precision Machining (link)

CNC Machining Terms to Know (link)

NIST Surface Finish Metrology Tutorial (link)