H-Grade (120°C), Black Epoxy NdFeB, Salt & Moisture Resistant
We offer Epoxy Coated “H” (High Coercivity) Neodymium Magnets designed for the high temperature working environments.
Standard Neodymium magnets face two major threats:
– Heat, which kills the magnetic field.
– Corrosion, which kills the magnet structure.
This product solves both simultaneously:
The Core:
– We use Grade 35H – 48H material, doped with Dysprosium to maintain magnetic stability up to 120°C (248°F).
The Shield:
– We coat the magnet in a premium Black Epoxy Coating.
– Unlike standard Nickel plating, Epoxy creates a hermetic plastic barrier.
– It seals the magnet against salt spray, humidity, and condensation.
Why Epoxy + H-Grade?
This combination is the industry standard for Automotive, Marine, and Outdoor Electronics.
Here is why:
1. Excellent Salt Spray Resistance (SST):
The Comparison:
– Standard Nickel (Ni-Cu-Ni) plating typically survives 24–48 hours in a Salt Spray Test before oxidation begins.
The Epoxy Advantage:
– Black Epoxy coating can withstand 200 – 500+ hours of salt spray exposure.
– If your device is used on a boat, in a coastal city, or outdoors in the rain, Epoxy is mandatory.
2. The “Glue” Factor (Adhesion):
The Pain Point:
– Nickel is slick.
– Glues often fail to bond with it, and cause magnets to drop out of their housing.
The Epoxy Advantage:
– Epoxy coating is resin-based.
– It has a natural affinity for industrial adhesives (Loctite, 3M, Araldite).
– Provides a “High Surface Energy” bond that is significantly stronger than gluing to Nickel.
Manufacturing Focus: Edge Condition
Epoxy is a paint-like coating.
It behaves differently than metal plating.
The “Rounded Edge” Requirement:
Observation:
Notice the rounded corners on the bar magnet in the photo.
The Reason:
Epoxy liquid pulls away from sharp corners due to surface tension (the “edge-thinning effect”).
If a magnet has sharp 90° edges, the coating will be too thin at the corners and will fail.
Our Process:
We heavily tumble/vibrate these H-Grade bars to create a generous radius (R-value) before coating.
This ensures the Epoxy wraps perfectly around the corners with uniform thickness.
Ideal Applications
Automotive Sensors: Under-hood sensors exposed to engine heat (100°C+) and road salts.
Marine Equipment: Latches and sensors on boats where salt air eats Nickel plating.
Outdoor Lighting: Magnetic fixtures exposed to rain and sun heat.
Wearable Tech: Connectors exposed to human sweat (which is corrosive) and body heat.
Ordering Guide: Specifying the Coating
To ensure quality, please define:
1). Dimensions: Length x Width x Thickness.
2). Grade: “Is 35H (Standard) sufficient, or do you need 42H/48H for higher torque?”
3). Adhesive Intention: “Will you be gluing this?” (We can ensure the Epoxy cure is compatible with your glue).
4). Cosmetic Standard: “Is this an internal part (Function only) or an external part (Must be scratch-free)?”
