What should an injection mold RFQ include?
A useful injection mold RFQ gives a supplier enough information to price the tool, review the part design, and plan validation without making hidden assumptions. Send the 3D CAD model, 2D drawing, resin grade, expected volume, quality requirements, target dates, and commercial scope. If one of these is missing, the first quote may look precise while important cost and schedule decisions remain unresolved.
1. Send a complete product definition
Start with the files that describe the part, not only a screenshot or a rough drawing. A supplier normally needs a native or neutral 3D model such as STEP or Parasolid, plus a 2D drawing in PDF or CAD format. The drawing should identify datums, critical dimensions, tolerances, surface finish, texture, color, and any features that affect assembly.
Mark critical-to-function dimensions separately from reference dimensions. Also identify threads, snap fits, sealing surfaces, optical areas, logos, and cosmetic faces. A note such as “tight tolerance” is not enough. State the actual tolerance or explain how the feature will be inspected.
For plastic parts, the tolerance system should match the part design and acceptance method. ISO 20457 covers tolerances and acceptance conditions for plastics moulded parts, but the final drawing still needs project-specific requirements [1].
2. Specify the resin and appearance requirements
“ABS” or “nylon” is only a material family. Include the exact commercial grade, supplier, color, filler or reinforcement, flame rating, and any required compliance information. If the part will contact skin, food, or a regulated product, state the applicable requirement before the tool is designed.
Describe appearance in terms a supplier can inspect. Include gloss or matte targets, texture reference, visible weld-line limits, gate vestige location, color standard, and allowable flow marks. A photograph can support the requirement, but it should not replace a written acceptance criterion.
Also state whether regrind is allowed, whether drying is mandatory, and whether the resin may change during the project. Material changes can affect shrinkage, warpage, cycle time, and the final mold design.
3. State volume, launch quantity, and tool-life expectations
Give three numbers when possible:
- Quantity for the first build or pilot run.
- Expected annual volume.
- Target tool life or total lifetime shots.
These numbers influence cavity count, steel selection, cooling layout, automation, spare inserts, and maintenance planning. If the annual volume is uncertain, provide a low and high case instead of forcing the supplier to guess.
Tell the supplier whether you prefer a single-cavity, family, or multi-cavity tool. The preference is useful, but it should not override a technical review. A family mold may reduce initial tooling cost while creating filling, balancing, or quality-control compromises.
4. Define quality requirements in an injection mold RFQ
List the characteristics that decide whether the part is acceptable. Typical examples include dimensional reports, appearance samples, leak testing, pull force, torque, assembly checks, and material certificates. State the inspection method, sample size, gauge or fixture responsibility, and approval process.
If the project uses a formal quality plan, mention it in the RFQ. Automotive programs may require PPAP or customer-specific requirements. Medical and electrical products may require additional traceability or compliance documents.
Injection conditions also matter during validation. ISO 294-1 describes general principles for determining injection moulding characteristics and molding test specimens [2]. The standard does not replace your project specification, but it is a useful reference when the supplier proposes a process-validation plan.
5. Set the schedule in milestones
Avoid asking only for a total lead time. List the dates that matter:
- Quote due date.
- DFM analysis review and design-freeze date.
- Tool design approval.
- First trial or T0/T1 sample.
- Pilot quantity and inspection report.
- Production release and shipment.
State which dates are fixed and which are targets. Include the time needed for drawing changes, sample shipment, customer feedback, and rework. A supplier cannot give a meaningful schedule without knowing how quickly the buyer will review DFM findings and approve samples.
6. Clarify the commercial and ownership terms
Ask what the quote includes. Separate tooling cost, sample parts, inspection, secondary operations, packaging, freight, taxes, and payment terms. Clarify whether hot runners, standard components, electrodes, spare inserts, and maintenance parts are included.
The RFQ should also state who owns the mold, where it will be stored, who may authorize changes, and how the supplier will protect the CAD files. If the tool may move to another factory later, define the handover documents and acceptance condition in advance.
A weak RFQ versus a decision-ready RFQ
| Item | Weak RFQ | Decision-ready RFQ |
|---|---|---|
| Part files | Screenshot or incomplete 3D file | 3D model, 2D drawing, datums, tolerances, and cosmetic areas |
| Material | “ABS” or “nylon” | Exact grade, supplier, color, filler, compliance, and drying requirement |
| Volume | “Large quantity” | Pilot quantity, annual volume range, and expected tool life |
| Quality | “High quality required” | Critical dimensions, inspection method, sample size, and approval criteria |
| Schedule | “As soon as possible” | DFM, design approval, trial, pilot, and production milestones |
| Commercial scope | One combined price | Tooling, samples, inspection, secondary work, freight, ownership, and terms separated |
What to ask for after sending an injection mold RFQ
Request a written list of assumptions with the quote. The supplier should identify the proposed mold base, steel or insert materials, cavity layout, gate concept, ejection approach, cooling assumptions, expected cycle time, and items excluded from the price.
Ask for a DFM report before the design is frozen. The review should cover draft, wall thickness, ribs and bosses, undercuts, weld lines, air traps, shrinkage, warpage risk, parting line, and ejection marks. A DFM review is most useful when it leads to a specific drawing change or an agreed acceptance trade-off.
How YIOT can support the review
At YIOT, we review the product files, material requirements, production volume, and quality criteria before starting mold manufacturing. Our services include DFM, Moldflow support, precision mold design and manufacturing, mold assembly, and OEM/ODM production. The final tooling plan and lead time depend on the part geometry, resin, cavity count, validation scope, and approved requirements.
Frequently asked questions
Can I request a quote with only a STEP file?
You can request a preliminary budget, but a firm quote usually needs a 2D drawing, material grade, volume, and quality requirements. Without them, the supplier must make assumptions that may change the final price.
Should I specify the cavity count in the RFQ?
State your production target and preferred approach, but ask the supplier to explain the cavity-count recommendation. The lowest initial tooling cost is not always the lowest cost per accepted part.
What if the product design is not finished?
Label the files as preliminary and request a budgetary quote plus a DFM review. Do not treat that quote as a fixed production price until the design, material, and acceptance criteria are frozen.
How many suppliers should receive the same RFQ?
Use the same file set and requirements for each supplier. This makes the technical and commercial comparison meaningful. Record every assumption that differs between quotes.
References
[1] ISO. *ISO 20457:2018 Plastics moulded parts – Tolerances and acceptance conditions.* https://www.iso.org/standard/68038.html
[2] ISO. *ISO 294-1:2017 Plastics – Determination of injection moulding characteristics – Part 1: General principles and moulding of multipurpose and bar test specimens.* https://www.iso.org/standard/68180.html
[3] ASTM International. *ASTM D3641 Standard Practice for Injection Molding Test Specimens of Thermoplastic Molding and Extrusion Materials.* https://www.astm.org/d3641-16.html
Have a project to review? Send your drawings and RFQ requirements to YIOT.