Interface Protection
Mark coating-sensitive surfaces, keep-out zones and functional interfaces on the drawing before tooling review.
Submit design requirementsOvermolded Magnetic Components
Injection-molded polymer encapsulates the magnet and integrates mounting features for pumps, sensors and other components. Select the magnet, resin and interfaces together, then validate dimensions, sealing and exposure resistance on the finished part.
Review the Complete Encapsulated Part
Specify the magnet grade, coating, polymer and molded interface. Include both operating conditions and the validation requirements for the complete part.
- Polymer designation, molding window and magnet position
- Interface pull/torque retention and dimensional datums
- IP67 validation, thermal cycling and chemical exposure
Product Range
Overmolded Magnets — Product Gallery
Product forms, uses and selection considerations. Final specifications are agreed for each project.
Overmolded Rotor
Magnet, polymer and shaft specified together.
Pump Rotor
Encapsulated format with service conditions validated.
Protected Cylinder
Plastic features for defined mounting and protection.
Impeller Magnet
Integrated impeller and magnetic element.
SELECTION GUIDEApplication selection notesExplore applications and requirements
Why Overmold?
Bonded NdFeB or sintered magnet + engineering polymer = the best of both materials.
- ✓Encapsulation for corrosion protection — polymer thickness, seams and adhesion influence protection; validate salt, steam and chemical exposure for the chosen material and complete part
- ✓Net-shape precision — molded features: snap-fit tabs, locating pins, gear teeth, threads — eliminating machined components
- ✓Automated assembly ready — consistent molded geometry can support automated feeding; handling fixtures and orientation features remain part of the line review
- ✓Food & medical grade options — select a documented resin grade and define the intended contact and sterilization conditions; a polymer family name does not approve a finished component
Applications
| Application | Typical Spec | Why This Material |
|---|---|---|
| Circulation Pump Rotors | Bonded NdFeB ring in PPO | Wet rotor designs — no seal needed, magnetic drive |
| Medical Pump Components | SmCo in PEEK | Validate sterilization cycles, media exposure and contact requirements |
| Automotive Sensor Targets | NdFeB in PA66 | Survives 150°C engine bay + road salt |
| Food Equipment Sensors | Ferrite in PPS | IP69K washdown target — finished-part validation required |
| Flow Meter Impellers | Bonded NdFeB in PPS | Review dimensional stability and corrosion resistance in the medium |
Overmolding Materials & Capabilities
Polymer and magnet combinations matched to your environment.
| Parameter | Options | Notes |
|---|---|---|
| Polymers | PA6/PA66, PPO (Noryl), PPS, PEEK, TPE | Food/medical: documented resin grade and end-use review |
| Magnets | Bonded NdFeB, sintered NdFeB (coated), SmCo, ferrite | Sintered requires coating before molding |
| Max size | Up to 150mm diameter | Insert molding press capacity |
| Tolerance | ±0.05mm molded dims | Critical features can be post-machined |
| Temperature | PA: 120°C / PPS: 180°C / PEEK: 250°C | Combined with magnet temp rating |
| Sealing | Up to IP67 / IP69K | IP67: IEC 60529; agree the applicable washdown standard and test separately |
Magnet Selection for Overmolding
The molding process constrains magnet choice:
- ✓Bonded NdFeB — the default choice — binder and magnetic grade must tolerate the actual insert thermal history; the published 180–300°C processing and ±0.1mm shape references are not universal compatibility limits
- ✓Sintered NdFeB — requires Ni-Cu-Ni or epoxy coating before molding; review resin melt temperature, mold temperature and transient insert temperature separately; evaluate magnetization sequence and post-mold magnetic properties
- ✓Ferrite — temperature-tolerant and cost-efficient; size is the constraint (ferrite is 3× the volume for equivalent flux)
Design for Overmolding
Get the most from insert molding with these guidelines:
- ✓Uniform wall — 1.5–3.0mm polymer wall for optimal fill and shrinkage control
- ✓Magnet retention — mold polymer over magnet shoulders or through-holes for mechanical interlock, not just adhesion
- ✓Mold flow direction — design gate location so polymer flows along (not across) the magnet — prevents displacement during injection
- ✓Sink marks — avoid thick polymer sections over the magnet; use ribs to maintain stiffness with uniform wall
Factory Tour
Inside Overmolded Magnets Manufacturing
Overmolded parts use insert preparation, controlled polymer forming, in-process visual checks and final interface inspection before tray packing.
4 process viewsProduct-specific manufacturing
1 inspection viewRelevant quality equipment
1 packing viewProduct-appropriate protection
End-to-end process visibilityManufacturing · inspection · packing documented in one focused route
Manufacturing processInspection & testingPacking & dispatch
Precision Insert Molding
Automated cells control insert loading, molding conditions and part handling.
High-Volume Molding Cells
Parallel machines support repeatable encapsulation and serial output.
Surface & Interface Inspection
Optical inspection checks cracks, voids, flash and molded interface quality.
Protected Component Packing
Separation and protective packing are defined for the component and shipment requirements.
Manufacturing, inspection and packing photographs for this product family.Equipment route varies by material and geometryRemote video inspection available before shipment
Frequently Asked Questions
Can sintered NdFeB be overmolded?
Yes, when the magnet grade, coating, resin and process are compatible. Melt temperature, mold temperature and the temperature reached by the insert are different quantities; a resin service-temperature value is not an injection-processing setting. Review exposure time, magnetization sequence, coating adhesion and post-mold magnetic output during process qualification.
How does overmolding compare to coating for corrosion protection?
The published 1–3mm polymer and 15–25µm coating thicknesses illustrate different protection routes. Overmolding can integrate mounting and protection, but thickness alone does not establish resistance to salt, steam or chemicals. Compare validated exposure performance, seams, interfaces, space and tooling cost for the application.
What's the tooling cost and lead time?
Tooling runs $3,000–$15,000 depending on size and complexity, with 4–6 weeks to first articles. For volumes above 50,000/year, tooling amortization typically pays back within the first year via eliminated coating and assembly operations.
Do you offer food-grade and medical-grade overmolding?
Food-contact and medical requirements are reviewed for the exact resin grade, additives, contact conditions and finished component. Request the applicable material declarations and test reports, and define cleaning, sterilization and packing requirements in the specification.
Overmolding Process Controls
Bond & Seal Integrity
Adhesion and wetting verified per tool qualification; seal tested to your IP or pressure spec for submersible and fluid-contact parts.
Thermal Management
Mold temperature profiles selected to protect magnet properties; post-mold magnetic verification confirms no degradation from the molding cycle.
Material Compatibility
Engineering polymers (PPS, PBT, PA, TPU) matched to your media and temperature; magnet substrate and coating selected for the overmold system.
Have an Assembly Drawing or BOM?
Send it to our team — we'll review the design and quote it as a validated, ready-to-install assembly.