Custom silicone overmolding around metal inserts, hardware and rigid metal structures for products requiring grip, sealing, protection, cushioning or integrated functional features. We support insert review, interface design, tooling, sampling, fit confirmation and repeat OEM/ODM production.
WHEN IT FITS
Suitable for metal handles or tools that require softer grip, comfort or controlled surface feel.
Suitable where silicone protects exposed metal edges, contact areas or hardware.
Suitable where silicone forms sealing or contact features around metal inserts.
Suitable for products combining metal hardware with flexible silicone in one assembled structure.
Suitable where silicone is used to cushion metal contact points or reduce direct surface impact.
Suitable for approved silicone + metal structures requiring consistent repeat production.
PROJECT INPUTS
The metal component and silicone interface should be reviewed before tooling to confirm geometry, retention method, fit, material compatibility and overmolding feasibility.
Sketches or 2D drawings with the metal structure and silicone areas.
CAD files of the insert and overmold geometry.
An existing part used as the structure and interface reference.
The metal part to be overmolded.
Alloy or material type reviewed for the interface.
Surface condition reviewed for overmolding performance.
Where silicone should cover, seal or grip.
Key dimensions and tolerance stack-up across materials.
Grip, sealing, protection or cushioning defined per use.
How the part fits the final assembly.
Market context reviewed for material and finish requirements.
INSERT & SURFACE
Metal surface condition can affect overmolding performance and should be reviewed before tooling.
Alloy and material type reviewed for the interface.
Insert shape reviewed for retention and flow.
Finish reviewed as part of the overmolding approach.
Coatings reviewed for their effect on the interface.
Clean insert surfaces reviewed before molding.
Contact areas reviewed for function and feel.
Retention features planned into the insert design.
Insert position defined and held during molding.
INTERFACE & RETENTION
The silicone-to-metal interface should be designed around retention, fit and function before mold development.
Retention features planned where direct bonding is not the approach.
Bonding area defined and sized for the requirement.
Locking features planned into the insert or overmold.
Insert located and supported throughout molding.
Contact surfaces reviewed for feel and function.
Coverage defined per the confirmed design.
Transition between metal edges and silicone defined.
How the part fits the final assembly reviewed.
DESIGN BEFORE TOOLING
Metal geometry reviewed for overmolding.
Overmold shapes and coverage planned.
Parting line placement agreed before tooling.
Shut-off area defined to control flow and flash.
Flash allowance and trimming reviewed per surface.
Insert location fixed and repeatable in the mold.
Overmold thickness balanced for coverage and cure.
Tolerance stack-up across metal and silicone reviewed.
Demolding sequence reviewed before tooling.
Metal surfaces protected during handling and molding.
TOOLING & SAMPLING
Each step is confirmed per project. Dedicated tooling and sampling support is described on the Tooling & Sampling capability page.
The drawing and metal insert are reviewed for overmolding.
Surface condition and interface approach are reviewed.
Mold structure, insert location and shut-off are reviewed.
Overmolding tooling is built around the confirmed design.
First samples are molded with the actual inserts.
Retention and fit are reviewed on samples.
Samples are checked for dimensions and function.
The approved sample becomes the production reference.
PRODUCTION
Production follows the approved sample and confirmed insert, interface and project specifications.
Inserts are prepared per the agreed interface approach.
Inserts are positioned and supported in the mold.
Silicone is overmolded per the agreed parameters.
Parts are cured to the confirmed state before handling.
Parts are removed and handled per the agreed method.
Flash is trimmed and surfaces finished per the agreed criteria.
Parts are checked against the approved sample.
Multi-part products assembled per project scope.
Parts packed per the agreed specification.
QUALITY FOCUS
Checks are aligned with the approved sample and agreed criteria — see the Quality Control capability.
Inserts positioned and retained as designed.
Retention reviewed on samples per the agreed approach.
Coverage matches the confirmed overmold geometry.
Flash kept within the agreed allowance.
Parting line finished per agreed surfaces.
Overmold thickness matches the confirmed design.
Surface quality consistent across batches.
Dimensions checked against the approved drawing.
Parts assemble into the product as intended.
Repeat orders produced against the approved sample.
APPLICATION DIRECTIONS
Typical directions where silicone + metal overmolding is applied.
Overmolded grips and handles around metal structures.
Metal hardware with integrated silicone areas.
Branded accessories combining metal and silicone.
Protection over metal edges and contact areas.
Interface components for devices and equipment.
Functional assemblies combining metal and silicone.
RELATED CAPABILITIES
Related manufacturing capabilities across the ESKY workflow.
Compression and transfer molding for silicone products and components.
Liquid silicone rubber molding for detailed geometry and repeat production.
Silicone overmolded onto plastic structures for grip, sealing and assembly.
Dedicated tooling and sampling built around the confirmed design.
Product development combining silicone with plastic, metal and other components.
Checks against the approved sample across production.
FAQS
SEND YOUR RFQ
Share your drawing, CAD file, metal insert details or reference sample. Tell us about the silicone areas, retention and interface requirements and estimated quantities.
PROJECT INTAKE
Share your insert details and drawings so we can review interface, retention, tooling and fit.