Injection Mold Design Guide Today
Pro Tip: Use a "draft analysis" in your CAD software. Color code surfaces that lack draft before you send the file to the shop.
The single biggest mistake novice designers make is designing a mold as if it were a solid block of steel. Plastic shrinks.
Every polymer has a specific shrinkage rate: injection mold design guide
Actionable Guide Rule:
Successful injection mold design requires balancing part requirements, material behavior, tooling cost, and production efficiency. Use DFM best practices, mold-flow simulation for complex parts, and prototyping to validate assumptions. Iterative refinement between part designers and mold makers will minimize risks and produce consistent, high-quality parts. Pro Tip: Use a "draft analysis" in your CAD software
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Related search suggestions will be prepared. The single biggest mistake novice designers make is
Your material dictates steel type, vent depth, and surface finish.
| Material | Shrinkage | Mold Steel | Vent Depth | Corrosion Risk | | :--- | :--- | :--- | :--- | :--- | | ABS | Low | P20 (standard) | 0.03mm – 0.05mm | Low | | PC (Polycarbonate) | Low | H13 / Stainless | 0.02mm – 0.03mm | Low (requires dry steel) | | PVC | High | Stainless (420) | 0.01mm – 0.02mm | High (releases HCl gas) | | POM (Acetal) | High | P20 / H13 | 0.01mm | Moderate (degassing needed) | | Glass-filled Nylon | Low | Hardened H13 | 0.02mm (abrasive) | Low (abrasive wear on gates) |
Critical Note for PVC/Plasticized materials: They off-gas. Your mold must have deep, easy-to-clean vents, and the steel must be stainless to prevent pitting corrosion.