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Mold Design Review & Approval
Use this injection mold design checklist after part DFM has been closed to review the actual mold-side design package. Confirm the cavity arrangement, mold base, parting concept, runner and gate, cooling circuits, venting, side actions, ejection, mold steel, inserts and serviceability before the mold drawing is approved.
The purpose is not to repeat part-design DFM or define trial and production acceptance criteria. It is to verify that the proposed mold structure is complete, internally consistent, traceable to the approved project requirements and supported by the engineering evidence needed for mold-design release.
Page boundary: this checklist reviews the mold-side design package. Detailed part DFM, formal RPN risk assessment, final steel-cut authorization, T0/T1 validation, FAI, PPAP and final mold acceptance belong to separate project stages and specialist pages.
Review Prerequisites
Mold design approval should begin only after the project inputs are aligned. The purpose of this step is to establish one controlled baseline for the part definition, material assumptions and mold requirements before the tooling team reviews the actual mold structure.
Major geometry, draft, undercut and manufacturability issues should already have a documented disposition.
The approved 2D drawing, 3D model, revision level, datums and CTQ references should describe the same product baseline.
Material grade, filler condition and project shrinkage basis should be defined before cavity and steel dimensions are reviewed.
Cavitation, runner concept, interface requirements, steel expectations and other project-level mold specifications should be available for comparison.
Mold Layout Review
Once the design baseline is controlled, review the overall mold architecture before evaluating individual tooling systems in detail. The layout should establish a practical cavity arrangement, mold base, parting concept, core and cavity structure, insert strategy and space for the mechanisms required by the part.
Confirm cavity count, part orientation, spacing and identification are consistent with the approved production and tooling concept.
Check mold-base size, parting direction, major shut-off regions and available space for the proposed mold structure.
Confirm the core/cavity split, major insert boundaries and replaceable or interchangeable features are clearly defined.
Reserve sufficient envelope for side actions, ejection, connections, service access and the intended molding-machine interface.
Minimum Layout Approval Evidence
| Layout Area | What to Verify | Evidence to Record |
|---|---|---|
| Cavity Arrangement | Count, orientation, spacing and cavity identification. | Approved mold-layout drawing or 3D assembly view. |
| Mold Base | Overall size, plate arrangement and available structural space. | Mold-base definition and layout revision. |
| Core / Cavity Structure | Parting concept, insert boundaries and major shut-off areas. | Section view, insert map or approved 3D structure. |
| Mechanism Envelope | Space for side actions, ejection, connections and service access. | Interference review or mechanism-layout evidence. |
Feed System & Venting Review
After the overall mold layout is established, confirm that the feed system and venting concept are compatible with the approved cavity arrangement, part requirements and mold architecture. The design review should document the selected runner system, gate strategy, expected flow path and venting locations before these features are released into the detailed mold design.
Confirm the cold-runner or hot-runner concept, feed arrangement and compatibility with the cavity layout.
Check that gate position and type are defined with the required appearance, functional and de-gating considerations.
Review the expected fill path and, for multi-cavity tools, whether the proposed feed concept supports balanced filling.
Confirm planned venting at expected end-of-fill regions, trapped-air areas and other locations identified during engineering review.
Minimum Feed-System Approval Evidence
| Review Area | What to Verify | Evidence to Record |
|---|---|---|
| Runner System | Architecture, feed route and compatibility with cavitation. | Approved runner layout or hot-runner system definition. |
| Gate Strategy | Gate type, location, access and expected vestige location. | Gate-location markup or approved mold-layout detail. |
| Flow Review | Expected flow direction, cavity balance and major interaction with part requirements. | Engineering review record or analysis evidence when required. |
| Venting | Planned vent locations and areas where trapped air requires specific review. | Venting markup or approved mold-design detail. |
Cooling System Review
Cooling should be reviewed as part of the mold design package, not added after the main structure is fixed. Confirm that the proposed circuits cover the core and cavity regions that require heat removal, fit around inserts and mechanisms, provide practical connections, and remain accessible for manufacturing and maintenance.
Confirm the cooling concept addresses the main core, cavity and insert regions identified in the mold layout.
Check that water routes do not conflict with inserts, fasteners, ejectors, side actions or other required mold features.
Define circuit grouping, inlet and outlet locations, connection points and identification needed for assembly and service.
Review whether plugs, connectors and service points remain practical to manufacture, inspect, clean and maintain.
Minimum Cooling-Layout Approval Evidence
| Review Area | What to Verify | Evidence to Record |
|---|---|---|
| Circuit Layout | Core, cavity and insert coverage within the approved mold structure. | Cooling-layout drawing or approved 3D circuit view. |
| Interference | Clearance from inserts, ejectors, fasteners and moving mechanisms. | Section view or interference-review record. |
| Connections | Inlet, outlet, circuit identification and external access. | Connector layout and circuit-ID reference. |
| Serviceability | Practical access for assembly, cleaning, repair and maintenance. | Design-review note or service-access markup. |
Mold Action & Ejection Review
Moving mechanisms and ejection should be reviewed together with the approved mold architecture. Confirm that sliders, lifters and other mold actions have a defined motion path and sufficient clearance, and that the ejection system can release the part without conflicting with inserts, cooling circuits or adjacent mechanisms.
Confirm motion direction, required travel, release sequence and the structural space available for each side action.
Review clearances, stops, retention features and potential interference with inserts, cooling and neighboring mechanisms.
Confirm ejector locations, support of critical part regions and compatibility with the core, inserts and visible surfaces.
Check that the mold can operate, assemble and be serviced without requiring avoidable access or disassembly complications.
Minimum Mold-Action and Ejection Approval Evidence
| Review Area | What to Verify | Evidence to Record |
|---|---|---|
| Side Actions | Motion direction, travel, release sequence and available mechanism envelope. | Slider / lifter layout or section view. |
| Interference | Clearance from inserts, cooling circuits, fasteners and other moving components. | Interference-check record or approved 3D review. |
| Ejection | Ejector distribution, contact areas and compatibility with the part and mold structure. | Ejector-layout drawing or approved design view. |
| Mechanical Access | Assembly, adjustment, replacement and maintenance access for moving components. | Service-access review or maintenance note. |
Materials, Inserts & Serviceability
Mold design approval should confirm that steel callouts, insert boundaries and service features match the approved tooling requirements. Review which components are integral, replaceable or interchangeable, and verify that wear-prone or service-critical areas can be accessed without unnecessary mold disassembly.
Confirm mold-base, core, cavity and insert material callouts are consistent with the approved specification and design BOM.
Check insert boundaries, retention, identification and the reason for using replaceable or separate tooling components.
Where inserts must be interchangeable, verify the locating, retention and identification concept is defined in the design.
Confirm wear items, inserts, connectors and service points can be inspected, removed or replaced with practical access.
Minimum Steel, Insert and Serviceability Approval Evidence
| Review Area | What to Verify | Evidence to Record |
|---|---|---|
| Steel / BOM | Material callouts and component definitions match the approved mold requirements. | Mold BOM, drawing callouts or material specification. |
| Insert Layout | Insert boundaries, retention and relationship to core/cavity structure. | Insert map, section view or approved 3D design. |
| Interchangeability | Locating, retention and identification approach where repeatable replacement is required. | Interchangeability note or approved insert detail. |
| Maintenance | Access to wear parts, service points and replaceable components. | Service-access review or maintenance reference. |
Drawing Approval & Evidence Control
The final mold-design review should show which drawing revision was reviewed, who owns each open item, what evidence supports the decision and whether the design requires revision or is ready for approval. This creates a traceable design record without turning the checklist into a steel-cut, trial or production-acceptance gate.
Each approval-critical row should reference the current mold drawing or 3D design revision and the engineering record used to support the review. Open comments should remain visible until the required revision or evidence has been completed.
Recommended design-review statuses are OPEN, REVISION REQUIRED, READY FOR APPROVAL and APPROVED. These describe the mold-design review state and should not be confused with final steel-cut GO / NO-GO authorization.
Record the mold drawing, 3D design and related specification revision reviewed.
Assign each unresolved design comment to a named engineering role or responsible party.
Link the approved drawing detail, review markup, analysis or design record supporting the decision.
Record whether the item remains open, requires revision or has been approved.
Minimum Mold-Design Approval Record
| Field | Purpose | Typical Record |
|---|---|---|
| Drawing Revision | Identify the exact mold design that was reviewed. | Drawing number / 3D revision. |
| Open Issue | Describe the unresolved design comment or required revision. | Issue ID / marked-up design note. |
| Owner & Evidence | Define responsibility and the record needed to support closure. | Owner / evidence reference / revision note. |
| Final Design Status | Record whether the mold design is still open or approved. | OPEN / REVISION REQUIRED / READY FOR APPROVAL / APPROVED. |
Mold Design Approval FAQ
These questions focus specifically on reviewing and approving the mold-side design package after the main part-manufacturability decisions have been addressed.
A mold design review should check the cavity arrangement, mold base, parting concept, runner and gate, venting, cooling circuits, sliders, lifters, ejection, steel callouts, inserts, interchangeability and service access. The review should also confirm that these design elements are consistent with the approved drawing, material basis and mold specification.
Before mold-design release, confirm the reviewed drawing revision, cavity and mold-base layout, major tooling systems, insert strategy and applicable engineering evidence. Any unresolved comment should have a responsible owner and disposition. The design status should clearly show whether revision is still required or whether the mold drawing is ready for formal approval.
Review cavity count and orientation, mold-base arrangement, parting direction, core and cavity structure, insert boundaries and the space required for mechanisms, ejection, cooling connections and service access. The purpose is to verify the complete mold architecture before detailed tooling systems are approved individually.
Review them within the complete mold assembly rather than as isolated components. Cooling circuits should fit around inserts and mechanisms; sliders and lifters should have defined motion and clearance; and ejectors should release the part without conflicts. Each system should have supporting layout or design evidence before approval.
Approval evidence may include the current mold-layout revision, 3D assembly views, section drawings, runner or gate markup, cooling layouts, mechanism reviews, insert details, BOM references and documented approval comments. Each critical checklist item should identify the reviewed revision, responsible owner, evidence reference and current design status.
Keep the checklist item open or mark it as revision required until the necessary design change or evidence is completed. If the issue requires formal prioritization, mitigation ownership and residual risk assessment, transfer it to the project risk register rather than turning the mold design checklist itself into an RPN scoring system.
Send the current 2D drawing, 3D model, resin information and available mold requirements. Our engineering team can review manufacturability concerns and tooling risks before the project moves further into mold design and construction.
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