Silicone + metal
Metal inserts and hardware combined with silicone for mounting, sealing and durable assemblies — with insert positioning and surface protection reviewed before tooling.
Where metal and silicone combine
When it fits
Soft-Touch Metal Handles
Suitable for metal handles or tools that require softer grip, comfort or controlled surface feel.
Protective Metal Inserts
Suitable where silicone protects exposed metal edges, contact areas or hardware.
Sealing Around Metal Features
Suitable where silicone forms sealing or contact features around metal inserts.
Integrated Hardware Components
Suitable for products combining metal hardware with flexible silicone in one assembled structure.
Shock / Contact Protection
Suitable where silicone is used to cushion metal contact points or reduce direct surface impact.
Repeat Multi-Material Production
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.
2D Drawing
Sketches or 2D drawings with the metal structure and silicone areas.
3D / CAD File
CAD files of the insert and overmold geometry.
Physical Sample
An existing part used as the structure and interface reference.
Metal Insert / Hardware
The metal part to be overmolded.
Metal Material Information
Alloy or material type reviewed for the interface.
Surface Condition / Finish
Surface condition reviewed for overmolding performance.
Silicone Area Definition
Where silicone should cover, seal or grip.
Dimensions & Tolerances
Key dimensions and tolerance stack-up across materials.
Functional Requirement
Grip, sealing, protection or cushioning defined per use.
Assembly Requirement
How the part fits the final assembly.
Target Market
Market context reviewed for material and finish requirements.
Insert & surface
Metal surface condition can affect overmolding performance and should be reviewed before tooling.
Metal Type
Alloy and material type reviewed for the interface.
Insert Geometry
Insert shape reviewed for retention and flow.
Surface Finish
Finish reviewed as part of the overmolding approach.
Coating / Plating
Coatings reviewed for their effect on the interface.
Cleanliness
Clean insert surfaces reviewed before molding.
Contact Area
Contact areas reviewed for function and feel.
Retention Features
Retention features planned into the insert design.
Insert Position
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.
Mechanical Retention
Retention features planned where direct bonding is not the approach.
Bonding Area
Bonding area defined and sized for the requirement.
Undercuts / Locking Features
Locking features planned into the insert or overmold.
Insert Positioning
Insert located and supported throughout molding.
Contact Surface
Contact surfaces reviewed for feel and function.
Silicone Coverage
Coverage defined per the confirmed design.
Edge Transition
Transition between metal edges and silicone defined.
Assembly Interface
How the part fits the final assembly reviewed.
Design before tooling
Metal Part Geometry
Metal geometry reviewed for overmolding.
Silicone Overmold Geometry
Overmold shapes and coverage planned.
Parting Line
Parting line placement agreed before tooling.
Shut-Off Area
Shut-off area defined to control flow and flash.
Flash Control
Flash allowance and trimming reviewed per surface.
Insert Location
Insert location fixed and repeatable in the mold.
Overmold Thickness
Overmold thickness balanced for coverage and cure.
Tolerance Stack-Up
Tolerance stack-up across metal and silicone reviewed.
Demolding Feasibility
Demolding sequence reviewed before tooling.
Metal Surface Protection
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.
Drawing / Insert Review
The drawing and metal insert are reviewed for overmolding.
Metal Surface / Interface Review
Surface condition and interface approach are reviewed.
Mold Structure Review
Mold structure, insert location and shut-off are reviewed.
Tooling Development
Overmolding tooling is built around the confirmed design.
First Sample
First samples are molded with the actual inserts.
Retention / Fit Review
Retention and fit are reviewed on samples.
Dimension / Function Check
Samples are checked for dimensions and function.
Customer Approval
The approved sample becomes the production reference.
Production
Production follows the approved sample and confirmed insert, interface and project specifications.
Metal Insert Preparation
Inserts are prepared per the agreed interface approach.
Insert Positioning
Inserts are positioned and supported in the mold.
Silicone Overmolding
Silicone is overmolded per the agreed parameters.
Curing
Parts are cured to the confirmed state before handling.
Demolding
Parts are removed and handled per the agreed method.
Trimming / Finishing
Flash is trimmed and surfaces finished per the agreed criteria.
Inspection
Parts are checked against the approved sample.
Assembly if Required
Multi-part products assembled per project scope.
Packaging
Parts packed per the agreed specification.
Quality focus
Checks are aligned with the approved sample and agreed criteria — see the Quality Control capability.
Insert Position
Inserts positioned and retained as designed.
Retention
Retention reviewed on samples per the agreed approach.
Silicone Coverage
Coverage matches the confirmed overmold geometry.
Flash Control
Flash kept within the agreed allowance.
Parting Line
Parting line finished per agreed surfaces.
Overmold Thickness
Overmold thickness matches the confirmed design.
Surface Finish
Surface quality consistent across batches.
Dimensions
Dimensions checked against the approved drawing.
Assembly Fit
Parts assemble into the product as intended.
Repeat Production Consistency
Repeat orders produced against the approved sample.
Application directions
Typical directions where silicone + metal overmolding is applied.
Tool / Handle Components
Overmolded grips and handles around metal structures.
Consumer Product Hardware
Metal hardware with integrated silicone areas.
Branded Multi-Material Accessories
Branded accessories combining metal and silicone.
Protective Metal Components
Protection over metal edges and contact areas.
Device / Equipment Interfaces
Interface components for devices and equipment.
Silicone + Metal Functional Assemblies
Functional assemblies combining metal and silicone.
Engineering notes from production programmes
- Cold-environment bonding: the bond approach is reviewed against the real service environment (for example cold outdoor use), not only ambient conditions.
- Premium integration: metal and silicone are finished as one product, with surface quality consistent across both materials.
Frequently asked questions
What metal inserts can be used for silicone overmolding?
Common inserts include stamped and machined metal hardware in various alloys; the insert is reviewed per project for geometry and surface condition.
Does silicone bond directly to every metal surface?
No. Bonding depends on the alloy, surface condition and insert design; where direct bonding is not suitable, mechanical retention or other approaches are used.
Can you develop an overmolded part from a metal sample?
Yes. Projects can start from drawings, CAD files or the metal sample; the insert and interface are reviewed before tooling.
Can silicone hardness and color be customized?
Yes. Hardness and color are selected per the application and confirmed on samples.
How do you keep the metal insert positioned during molding?
The insert location is fixed and supported in the mold, and the positioning is reviewed at the mold structure stage.
Can mechanical retention be used instead of direct bonding?
Yes. Undercuts, holes and locking features can be designed into the insert so the silicone is mechanically retained.
How do you confirm fit and retention before production?
First samples are reviewed for retention, fit, dimensions and appearance before customer approval.
What information is needed for quotation?
The metal insert details or sample, drawings, silicone area definition, hardness and color expectations, quantities and packaging expectations.
Where to go next
Combining metal and silicone?
Send the insert geometry and silicone requirements. We review positioning and retention, then reply with the next steps.