An accurate injection mold quotation starts with an accurate RFQ. When the project information is incomplete, suppliers have to make assumptions about the part, mold, material, machine, and quality requirements. Those assumptions can produce quotations that look comparable but actually describe very different tools.
This checklist shows what buyers should send when requesting an injection mold quote. You do not need to have every answer before contacting a supplier, but clearly marking unknown items is much better than leaving them open to interpretation.
1. Part files and drawing information
Send the latest controlled version of the product data. STEP or Parasolid files are widely used for 3D review, while a 2D drawing is still important for tolerances and notes.
- 3D model with file revision;
- 2D drawing in PDF or DWG format;
- assembly drawing, if the part fits with other components;
- critical-to-quality dimensions clearly marked;
- general tolerance standard;
- part weight or target weight, if known;
- reference samples or photos of an existing part.
If the design is not final, state which areas are still open. A supplier can often begin a preliminary review, but the quotation should identify the assumptions used.
2. Product application
Explain what the part does and where it will be used. Application details help the engineering team understand appearance, strength, temperature, chemical exposure, assembly, and regulatory requirements.
Useful information includes whether the part is an automotive exterior component, an appliance housing, a packaging product, an electrical enclosure, or an internal structural component. State whether it is visible to the end user and whether any surfaces are cosmetic.
3. Plastic material and color
Provide the exact resin grade whenever it has already been selected. “ABS” or “PP” alone may not be enough because different grades have different flow, shrinkage, impact, flame, UV, and appearance properties.
- resin manufacturer and grade;
- virgin, recycled, or mixed material requirement;
- glass-fiber or mineral content;
- color reference, masterbatch, or RAL/Pantone target;
- flame, UV, food-contact, or other specified requirement;
- approved alternative materials, if any.
If the material has not been selected, explain the required performance and let the supplier offer options. Final material approval should remain with the product owner.
4. Surface finish and appearance standard
Surface requirements influence steel selection, draft, polishing, texture, parting lines, gate position, and mold cost.
Specify polished, matte, EDM, textured, painted, plated, or printed surfaces. Mark appearance zones on the drawing and identify areas where ejector marks, weld lines, gate marks, or parting lines are restricted. If a texture standard is required, provide the texture code and confirm the related draft angle.
5. Production volume and mold-life target
Annual volume helps the supplier choose cavity count, steel, runner system, automation level, and mold construction. Provide:
- forecast annual quantity;
- maximum monthly demand;
- expected program life;
- required mold life or shot target;
- planned working hours and maintenance conditions.
A high-volume tool should not be specified in the same way as a prototype or bridge-production mold. Mold-life figures should always be connected to approved material, process, and preventive maintenance.
6. Cavity count and runner preference
If you already know the required cavity count, include it in the RFQ. Otherwise, provide the demand, machine data, part size, and cycle target so the supplier can propose a layout.
Also state whether you prefer a cold runner, hot runner, valve gate, or a specific hot runner brand. For family molds, identify which parts must be produced together and the required quantity ratio.
7. Destination injection machine
Machine information should be provided before mold design, not after the mold is built. Include the machine model and, where possible:
- clamping force;
- tie-bar spacing and platen dimensions;
- minimum and maximum mold height;
- maximum daylight and opening stroke;
- screw diameter and shot capacity;
- locating-ring diameter and nozzle radius;
- ejector pattern and ejector stroke;
- available hydraulic and electrical connections;
- hot runner voltage and connector standard;
- water and air fitting standards.
If no machine has been selected, ask the supplier to recommend the required machine range and state the assumptions in the proposal.
8. Mold construction standard
Attach your company mold standard if one is available. Otherwise, identify the required mold base, steel grades, hardness, component standards, hot runner brand, connectors, lifting requirements, and engraving.
Also confirm whether the mold will remain in China for molding or be exported. Export molds often require different fittings, safety labels, lifting points, documentation, and spare parts.
9. Dimensional and quality requirements
Mark the dimensions and product characteristics that control function. Do not simply mark every dimension as critical because that makes inspection expensive without improving decision-making.
Specify the required inspection method and documents, such as:
- full dimensional report or selected critical dimensions;
- CMM, optical, gauge, or fixture inspection;
- material certificate;
- color or gloss measurement;
- assembly and functional test;
- FAI, PPAP, capability study, or customer-specific format;
- approved sample retention.
10. Trial material, samples, and approval
Define who supplies the production resin for mold trials and how much material is available. State the sample quantities needed at each stage and the shipping address.
The RFQ should also explain the approval process. Will approval be based on dimensions, assembly, appearance, function, customer testing, or a combination? Identify who has final approval authority and whether a signed sample is required.
11. Secondary operations and assembly
List any work that happens after molding, including painting, printing, laser marking, plating, welding, insert installation, assembly, leak testing, or packaging. These operations can affect part design, gate location, holding fixtures, and inspection.
12. Schedule and commercial information
Provide the target date for first samples and the required production date. If the date is fixed, explain why so the supplier can identify the real critical path.
Commercial information should include delivery location, Incoterms if specified, preferred currency, packing requirements, and whether the quotation should include freight, duties, or molding production.
13. Confidentiality and file control
If the project is confidential, send an NDA before transmitting sensitive product data. Give every drawing and model a revision number and identify the current approved version. When files change, issue a short change summary instead of relying only on a new attachment name.
Injection mold RFQ summary table
| RFQ item | Information to provide | Why it matters |
|---|---|---|
| Part data | 3D, 2D, revision, assembly information | Defines geometry and tolerances |
| Application | Use conditions and appearance zones | Guides risk review and finish |
| Material | Supplier, grade, color, additives | Affects shrinkage, flow, and steel choice |
| Volume | Annual and monthly demand | Guides cavity count and mold construction |
| Mold standard | Steel, components, runner, mold life | Makes quotations comparable |
| Machine | Platen, tie bars, shot, ejector, connections | Ensures the mold can run at destination |
| Quality | Critical dimensions and report format | Defines approval evidence |
| Trial | Material, sample quantity, approval stages | Prevents delay after tool completion |
| Delivery | Location, date, packing, shipping scope | Defines the complete commercial offer |
Common RFQ mistakes
- Sending only an image or an STL file without tolerances.
- Requesting a production quote before material and annual volume are known.
- Comparing quotations without checking steel, components, cavities, and runner type.
- Providing machine information only after mold design approval.
- Changing the 3D model without a revision notice.
- Asking for a guaranteed cycle time without defining material, machine, cooling water, and acceptance conditions.
Frequently asked questions
Can I request a quote without a final 3D model?
Yes, but the quotation will be preliminary. Clearly identify open design points and request an updated quotation after the product data is released.
Do I need to specify the mold steel?
Not always. If you do not have a company standard, provide volume, material, finish, mold life, destination, and maintenance expectations. The supplier can recommend steel, but the quotation should explain the recommendation.
Why do mold quotations vary so much?
Differences may come from cavity count, mold size, steel, hardness, hot runner, standard components, machining hours, inspection, trial scope, project risk, and after-sales support. A detailed RFQ makes these differences visible.
Next step
After collecting the information above, send the same controlled RFQ package to a short list of qualified suppliers. Ask each supplier to list assumptions and exclusions. This produces a more useful technical comparison and reduces expensive changes after the order.
Mingyu Mold can review your part data through its injection mold design and DFM process. When sending a request, include the 3D model, resin, annual volume, critical requirements, and destination machine information whenever available.
