Adrian and Paul, Sofeast’s Head of New Product Development, unpack why injection moulding costs spiral, often due to needlessly tight tolerances on non-critical features and vanity finishes, and then lay out three practical levers to pull:
- Smarter part design & DFM (uniform walls, real draft, smart gates, right resin)
- Good tooling choices (P20 vs H13, cavity count, hot vs cold runners)
- On-line process discipline (match press tonnage, sensible regrind limits, SPC/sensors, in-tool de-gating)
Paul closes by myth-busting common assumptions about moulding and cost.
Listen here
Listen to the episode or watch on YouTube
Episode Sections:
- 00:00 Intro & today’s topic
- 01:58 Why costs balloon: tolerances & cosmetics
- 06:52 Lever #1 — Design & DFM (wall thicknesses, material choice)
- 14:40 Lever #2 — Tooling decisions (steel grades, cavities)
- 22:44 Lever #3 — Processing & production setup
- 27:35 Myth-busting: cheap tools, mirror finishes, family molds
- 31:23 Recap & where the biggest savings really are
Cost-Saving FAQs
- How do I decide which dimensions get tight tolerances?
Map tolerances to CTQs only (fit, function, sealing, assembly). Everything else should use standard mold-maker recommendations to keep tooling simple and cycles fast. - When is a hot runner worth it?
When volume is high, color is stable, and balancing cavities for cosmetic parts matters. It reduces runner waste and often shortens cycles. - Can I start with a cheaper tool and “fix it later”?
Bridge tools are fine if you’re honest about resin, volume, and finish needs, but choose reputable steels and machining standards to avoid chasing defects. - How much regrind is safe?
It depends on resin and part criticality. Set conservative caps for cosmetic/structural parts, and validate with mechanical tests during pilot runs.
Extra resources to dive deeper
- Product Tooling: Possible To Avoid Paying for it in Full?
- Common Design For Manufacture Improvements On Plastic Injection Molded Parts
- When To Sign Off On Injection Mold Tooling? Inside the Journey from DFM to T0→T2 [Podcast]
- Plastic Playbook: Choosing The Right Polymer [Podcast]
- Mold Tooling Ownership: The term Chinese suppliers push for will shock you!
- The Conundrum of Investing in Tooling Before a Final Prototype
🎧 Listen, rate, & subscribe to the ‘China Manufacturing Decoded’ podcast on your favorite provider
More episodes are on the way, so remember to rate us and subscribe! You can find us on:
- Apple Podcasts
- Spotify
- TuneIn
- Amazon Podcasts
- Deezer
- iHeartRADIO
- PlayerFM
- Listen Notes
- Podcast Addict
- Podchaser
- The podcast’s website at China Manufacturing Decoded