Injection Molding Quote Checklist: CAD, Resin and Sample Approval

Build a practical injection molding RFQ that identifies the released design, resin grade, cosmetic requirements, tooling questions and sample acceptance checks.

Release the model and drawing as one revision

An injection molding quote is easier to assess when every supplier reviews the same part. Give the part a number and revision, export the intended solid model, and add a PDF drawing with the requirements that geometry alone cannot explain.

Use the drawing to identify critical dimensions, material, finish, inserts and other secondary work. Include the product assembly or mating interfaces where they clarify a fit requirement. Archive superseded versions so there is no ambiguity about which design should be reviewed.

The DIYIPCB injection molding form recommends a ZIP containing STEP/STP data and a PDF drawing. If an enquiry starts before the design is finished, list the unresolved items and distinguish a budget discussion from an approved manufacturing release.

Describe resin, color and the use environment

Specify the resin grade if it is fixed. Otherwise, describe the intended use and ask for a material proposal. Provide the requirements behind the choice: temperature, impact, chemical contact, appearance or another functional condition.

Identify the color reference and whether matching requires an agreed physical sample. State any filler, approved-source or documentation requirement. A quotation for a broad material family should not be mistaken for confirmation of a particular qualified grade.

If a requirement is mandatory, label it as such and identify the evidence needed for acceptance. If it is a preference, say so. This makes it easier to assess proposed alternatives without accidentally changing the product specification.

Ask focused design-for-manufacturing questions

Request feedback on the features that may affect molding or tooling, then review that feedback against the product requirements. Avoid imposing a generic wall thickness or draft value without considering the resin, geometry and intended surface.

Wall transitions, ribs and local material concentrations deserve review; manufacturer guidance discusses how wall thickness affects molded-part design. Ask for proposed changes on your model rather than applying one rule to every feature.

• Which dimensions or surfaces would change if draft is added?
• Are there features that need a different parting strategy or additional mold actions?
• Which faces must be protected from unacceptable gate or ejection marks?
• Could a proposed change affect the lid, mounting points, seal or connector clearance?

Record the answers and issue revised files when changes are accepted. A marked-up screenshot helps discussion, but the final production package should contain the agreed geometry.

Make tooling and commercial scope comparable

Ask for tooling and molded-part costs separately. Record the proposed cavity count, sample scope, production quantity and included secondary operations. If alternatives are offered, label the differences so you can compare like with like.

Clarify how tooling changes would be handled, what sample iterations are included, and what inspection records will accompany the agreed work. For a longer program, ask about mold ownership, storage, maintenance and the process for future repeat orders. These are terms to agree for the project, not assumptions to leave until after tool completion.

State the current order quantity and expected total quantity independently. If total demand is uncertain, describe it as a planning estimate. This gives the review team useful context without turning a forecast into an unintended purchase commitment.

Define sample approval before the samples arrive

Create a short acceptance plan tied to the drawing. Name the dimensions that must be reported, the mating parts to use for assembly checks, and the visible surfaces to review. Decide who can approve the result and what evidence they need.

Keep dimensional, functional and cosmetic checks distinct. A part can look acceptable but fail to assemble; it can also fit correctly while missing a specified appearance requirement. Test the properties relevant to your product rather than assuming one type of approval covers everything.

If samples need correction, list each issue, its drawing reference and the agreed action. Keep any changed requirement separate from a manufacturing deviation. That distinction helps prevent an approved sample from becoming an unclear substitute for the released specification.

Use a complete enquiry summary

Part/revision: [reference]. Model and drawing: [files]. Resin/grade: [specified or propose]. Color/finish: [reference]. First batch: [quantity]. Expected demand: [estimate]. Tooling: [new or existing for review]. Critical checks: [drawing references]. Sample approval: [tests and approver]. Target delivery: [date and destination]. Open questions: [list].

Before authorizing tooling or production, confirm which requirements have been accepted, which remain open, and what the quotation includes. A clear enquiry reduces avoidable clarification and gives both sides a consistent record for samples and later orders.