Injection molding RFQ checklist: what to send with your CAD model

A useful injection molding request for quotation (RFQ) explains what the part must do, what is already decided, and what still needs engineering review. Send the current CAD model together with drawings, known material requirements, quantities, finishing needs and acceptance criteria. Put unanswered questions in a separate list so a supplier can identify assumptions before you compare prices.

Concept illustration: a plastic enclosure and quotation documents. The image is AI-generated and is not a customer part or production drawing.

What belongs in an injection molding RFQ?

Organize the request into six sections below. You do not need to solve every design question before starting a conversation. You do need to distinguish an approved requirement from a preference or an estimate.

1. A controlled set of part files

• Part number, description, revision and a contact for technical questions.
• The current 3D model and available 2D drawing, with units clearly identified.
• Mating-part information or an assembly view when fit affects the design.
• Whether the request is for new tooling, a design revision or production using an existing mold.

Ask which file formats the supplier needs. If you have a sample or existing mold, describe it and agree what additional information is required. Geometry, drawings, samples and tooling status are among the inputs covered in Rodon's quote-preparation questions; its specific production policies should not be assumed to apply to another molder.

2. Material and application requirements

If a material is specified, provide the manufacturer, trade name, exact grade, color requirement and relevant technical datasheet. State any required documentation or restrictions. A resin family alone does not identify a particular grade. Protolabs' material-information requirements illustrate the level of identification used when discussing a specified material.

If material selection is open, mark it needs review. Describe the part's use, expected environment, contact with other substances, appearance needs and functional demands. Ask for a material discussion; do not quietly turn an unconfirmed resin preference into the quotation baseline.

3. Quantities that separate today from the forecast

List the initial order quantity, anticipated repeat-order quantities, estimated annual demand and expected program life, where known. Identify which numbers are firm and which are planning estimates. An annual forecast is not the same as one purchase order. These distinctions also appear in Midstate Mold & Engineering's RFQ form.

For a developing product, explain whether the first parts are for evaluation, a pilot build or saleable production. Our guide to low-volume injection molding gives additional context for discussing early production needs. Ask the supplier to identify the quantities and assumptions used in its quote.

4. Critical features and acceptance requirements

Call out the features that control fit, function and assembly on the drawing. Include the specified tolerances and reference requirements rather than asking for every feature to be “as tight as possible.” Explain what evidence you need when reviewing samples and what records, if any, must accompany production.

Inspection scope should be agreed explicitly. For example, Protolabs' inspection documentation describes customer-selected critical features on a 2D drawing. It does not establish what inspection package another supplier offers. Ask Ronningen to confirm the feasibility and scope of your own requirements.

5. Appearance, finishing and work after molding

Identify visible surfaces, color references, texture or finish specifications, markings and assembly needs. State whether the quotation should include those operations or cover molded parts alone. If you supply a visual reference, explain which attributes it is intended to represent.

Material, finish, quantity and requested timing are explicit inputs in Protolabs' manufacturing-analysis guidance. Review Ronningen's manufacturing services to identify supporting operations to discuss, then ask the team to confirm what belongs in your project scope.

6. Timing, packaging and quotation assumptions

Provide your desired sample date and production need date, labeling them as requested dates rather than agreed commitments. Include the delivery destination and any known packaging, identification or handling requirements.

Ask the quotation to distinguish tooling, parts, secondary operations, inspection, packaging and shipping where applicable. Also ask what is excluded and which open decisions could change the price or timing. This comparison format is a planning aid; the supplier must confirm the terms it can offer.

Use a decision-status worksheet

For each item, choose confirmed, needs review or not applicable. Add the supporting file and revision, or name the person who will resolve the question. “Not applicable” should be an intentional decision, not a substitute for missing information.

Quotation package worksheet

Item	What to record	Status to assign
Model and drawing	Part number, matching revision, units and file names	Confirmed / needs review / not applicable
Material	Specified grade and datasheet, or application questions	Confirmed / needs review / not applicable
Quantities	First order, repeat demand and forecast confidence	Confirmed / needs review / not applicable
Acceptance	Critical features, sample review and required records	Confirmed / needs review / not applicable
Finishing and assembly	Appearance references and included operations	Confirmed / needs review / not applicable
Delivery	Requested dates, destination and packaging needs	Confirmed / needs review / not applicable

Example: a cover with an undecided material

Suppose a fictional enclosure cover has a released drawing but its material is still under review. Your worksheet could say:

• Files — confirmed: cover model and drawing, both revision B; units shown on the drawing.
• Material — needs review: application requirements attached; no resin grade approved yet.
• Quantities — needs review: request a pilot-build discussion; purchasing will confirm order quantity and forecast.
• Acceptance — needs review: mating features identified; sample inspection and approval plan still to be agreed.

The useful next step is clear: discuss the open decisions and label any preliminary quote assumptions. Filling the empty boxes with guesses would make the package look more complete without making it more reliable.

Keep design changes tied to the quote

Before sending files, check that the model, drawing and supporting specifications describe the same revision. If one is ahead of another, say so explicitly. When a design changes, ask whether the earlier quotation still applies and record the response before proceeding.

Manufacturer review practices, such as Fictiv's DFM review and approval process, show why revisions and unresolved design decisions need to remain visible before tooling. For geometry questions, continue with our design for manufacturability guide; this RFQ checklist is for organizing the request, not replacing engineering review.

Start the quotation discussion

Send Ronningen a short project summary covering the part's purpose, known material requirements, quantities and requested timing. Note which files you have and which questions remain open. Contact the Ronningen team to agree how to share drawings and confirm the next steps. The inquiry form below is a starting point for that conversation.