From repeat failures to zero defects, with one material change.
- Growth Madrigal
- Aug 8, 2025
- 2 min read
Last year, a global electronics OEM reached out to us with a frustrating issue:A connector in their flagship product kept failing every 2 months under regular use.
The failure wasn’t in the design. It wasn’t the plastic. It was in the way the metal insert and plastic shell were assembled.
So we proposed a change: not to the material, but to the method.
We moved the part from insert-moulding to overmoulding.
Why insert-moulding may be your weak link:
The client’s original process used an insert-moulded brass terminal, manually placed before moulding the outer shell.
But over time, usage stresses led to:
Loosening between the plastic and insert
Micro-cracks around the press-fit zone
Cumulative stress failure every 60–75 days
Our client was spending on warranty claims, rework, and manual inspection, and it was slowing their launch roadmap.
How an overmoulding switch solved all the manufacturing problems:
We re-engineered the part for overmoulding: using the same metal insert, same plastic, and the same interface.
What changed:
The insert was anchored during the first shot
A second shot enveloped the structure with a thermoplastic elastomer
Bond strength increased by 3.2x (lab tested), and field rejections dropped to zero
With zero design change and no new material formulation, we created a sealed, unified part that could handle repeated flex and pressure.
The result: No redesign. Just reliability.
Rejection rate: Dropped from 8.5% to under 0.3%
Lifetime cycles: Increased by 4x
Manual fitment: Eliminated
Post-moulding inspection time: Cut by 60%
And the part is still in production, with zero reported failures a year later.
Want to run a re-evaluation on your insert-moulded parts? Reach out and we’ll make it happen.
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