High stability small lightweight Black Epoxy-Coated sintered Ring Magnet

1. Product Overview 

Engineered for durability and precision, our Precision customized high stability small lightweight black epoxy coating sintered ring magnet is designed to deliver stable magnetic performance in demanding industrial environments. Manufactured with high-quality ferrite material and coated with a corrosion-resistant black epoxy, these magnets combine strong magnetic force with long-term reliability.

Key Features:

High Magnetic Stability: Consistent performance for positioning, holding, and inductive applications.

Durable Epoxy Coating: Protects against moisture, chemicals, and mechanical wear.

Precise Dimensions: Machined to tight tolerances for easy integration into assemblies.

Low Magnetic Loss: Excellent for long-term static and dynamic magnetic field use.

Custom Sizes Available: Inner/outer diameter and thickness can be tailored to your needs.

2. Technical Specifications

Product Name: High stability small lightweight Black Epoxy-Coated sintered Ring Magnet

Magnet Grade: N45 (Br ≥ 14.8 KGs, Hcj ≥ 10.5 KOe) — Customizable

Dimensions: D12 - D10 x 5 mm

Tolerance: ±0.05 mm (Length, Width, Thickness)

Operating Temperature: ≤ 80°C (Customizable high-temp versions available)

Density: ≥7.5 g/cm³

Surface Magnetic Field: 2400 Gauss (Measured using Japan TM-801 Gauss meter)

Magnetic Flux: 2.2 mWb (Measured; value varies by material grade)

3.Surface Treatment & Coating Technology

To enhance this strong magnetic force high stability compact size lightweight black epoxy coating sintered ring magnet’s corrosion resistance, surface quality, and magnetic stability, the following treatments are used:

- Cleaning & Degreasing:  

  Ultrasonic cleaning with alcohol/specialized solvents

4.Appearance & Dimensional Inspection

Visual Inspection: Under standardized lighting, trained QC staff check for cracks, chipping, inclusions, pores, or oxidation.

Automated Intelligent Inspection: High-speed cameras with AI algorithms detect and reject defects (e.g., cracks, scratches, discoloration) and dimensional anomalies, improving yield and reducing human error.

5.Reliability Testing

To ensure this super strong magnet stable small lightweight black epoxy coating sintered ring magnet  maintain excellent corrosion resistance in complex or harsh environments, the salt spray test is an essential accelerated aging method. It simulates long-term exposure to marine climates, industrial pollution, humidity, or acidic and alkaline conditions, allowing for a reliable evaluation of the protective performance and durability of the magnet's surface coating.

  6.  Packaging & Transportation

Defect Elimination: 100% inspection using calipers, projectors, visual checks, and automated systems to reject cracked, chipped, oxidized, or coated-defective magnets.

Uniform Magnetization & Structured Arrangement: Magnets are uniformly magnetized and arranged for optimal packaging based on customer requirements to ensure performance and facilitate automated assembly.

Vacuum Sealed Packaging: Multi-layer vacuum sealing with moisture barriers, desiccants or nitrogen, prevents corrosion and magnetic interference during storage and shipping.

Customized Outer Packaging: Shock-proof, moisture-resistant, and anti-magnetic leakage packaging (e.g., multilayer cartons, plastic boxes, metal shielding) ensures compliance with international logistics standards. Each box includes a product list, labels, and tracking codes.

We know logistics is more than moving goods — it’s about delivering your promise. Our trusted solutions offer:

Global shipping coverage

Real-time tracking from origin to destination

Enhanced safety at every stage

Dedicated service with customized shipping plans

With our robust land, sea, and air network, your business moves faster, safer, and with complete confidence.

7.FAQ

Q. What is an epoxy-coated ring magnet?

It is a ring-shaped magnet (typically ferrite or NdFeB) with a protective black epoxy coating. The coating improves corrosion resistance and mechanical durability.

Q. Will the epoxy coating affect the magnet’s performance?

No, the epoxy layer is non-magnetic and thin. It protects the magnet without affecting its field strength.

8. Application Fields

Inductors & Transformers

Application: Commonly used in toroidal cores for chokes, common mode inductors, and EMI filters.

Benefits:

Reduces eddy current losses

Enhances electromagnetic interference suppression

Supports automated coil winding with consistent dimensions 

 Sensors & Magnetic Encoders

Application: Used in Hall sensors, rotary encoders, and angular position feedback systems.

Benefits:

Delivers uniform magnetic flux for precise signal output

Maintains magnetic stability under varying temperatures

Supports custom pole orientation and sensor alignment  

Magnetic Couplings & Mounting Systems

Application: Applied in magnetic mounts, rotating couplers, and quick-lock assemblies.

Benefits:

Enables non-contact, reliable magnetic connection

Epoxy surface resists mechanical wear from repeated usage

 Consumer Electronics & Smart Devices

Application: Used in magnetic accessories, wireless charging bases, and compact enclosures.

Benefits:

Sleek, compact shape fits within slim product profiles

Coated for safe contact with plastics and electronics

Eco-compliant materials suitable for international consumer markets

1. Why Choose us ？

Dongguan Jinconn New Materials Co., Ltd. is a publicly listed enterprise offering integrated R&D, manufacturing, and sales of rare earth magnets. Based in Xiaohe Industrial Zone, Daojiao Town, Dongguan, we serve clients across China and globally.

 20+ years of magnet manufacturing expertise

 Strict quality control & customization capability

 Multilingual technical support with global delivery

 RoHS and REACH compliant 

Please contact us for free samples, magnet customization solutions, and MSDSRoHS, ISO 9001, QC080000, IATF 16949, ISO 14001, ISO 27001 or other relevant certificates! 

10.  Usage Precautions

⚠ Safety & Handling Guidelines

Handle with care: Neodymium magnets are brittle and can chip or crack if dropped or impacted.

Avoid injury: Always slide magnets apart—do not force or pry them to separate.

Check polarity before use: Incorrect installation may cause malfunction or damage to equipment.

Store properly: Keep in a dry, neutral environment; avoid contact with moisture, acids, or corrosive substances.

Keep away from sensitive electronics: Do not place near hard drives, magnetic cards, pacemakers, or similar devices.

11. Customization & Services

Customizable magnet dimensions, geometry, and surface coatings (including layer count, thickness, and color)

Precision magnetization orientation and adjustable magnetic field intensity

Optional laser marking for logos, part numbers, or traceability codes

Specialized packaging and pull-force testing tailored to your application needs

With deep expertise in magnetic materials, we deliver solutions for industries like EVs, smart manufacturing, and electronics. Our strong technical capabilities and product consistency have earned the trust of customers worldwide.

·  Precision Magnetics, Tailored for Performance.

If you have any magnet-related needs, we offer free customized magnet services. Please feel free to contact us at any time.

Contact Us：

 Phone/WhatsApp/WeChat: +86 13829120676

 Email: Info@jinconn.com

 Address: Xiaohe Industrial Zone, Daojiao Town, Dongguan City, Guangdong Province, China.