1. Product Overview

The Ni-Cu-Ni coated countersunk NdFeB magnet is a high-performance permanent magnet featuring a countersunk hole design for secure mechanical fastening. It is manufactured using high-grade NdFeB material (e.g., N35–N52) and coated with triple-layer nickel plating (Ni-Cu-Ni), significantly improving corrosion resistance and surface durability. It is ideal for applications requiring both strong magnetic performance and robust mechanical mounting.

2. Technical Parameters

- Product Name: Counter sunk Magnet

- Magnet Grade: N40 (Br ≥ 13.2 KGs, Hcj ≥ 10.8 KOe)

- Dimensions: D12*4.5/D9.5*2.5

- Dimensional Tolerances: Length ±0.05mm, Width ±0.05mm, Thickness ±0.05mm

- Working Temperature: ≤ 80°C (custom high-temperature versions available)

- Density: ≥ 7.5 g/cm³

- Surface Magnetic Field: 3500 Gauss (measured with TM-801 Gauss meter, Japan)

- Magnetic Flux: 1.5mWb (measured with fluxmeter)

3. Manufacturing Process

Countersunk Hole Drilling:
High-precision CNC or automated drilling ensures consistent hole diameter, depth, and countersink angle.

Magnetization Process:
Professional pulse magnetization equipment is used to inject strong and stable magnetic fields, ensuring the magnet meets design specifications and performs reliably under high load or high-frequency operation.

Grinding & Fine Finishing:
Advanced precision equipment grinds the magnet surface to ensure smoothness and tight dimensional tolerances, supporting high-precision industrial applications.

4. Surface Treatment & Plating Technologies

Epoxy Coating:
Offers enhanced chemical resistance and waterproofing, especially suitable for humid environments.

Triple Nickel Plating:
Ni-Cu-Ni electroplating dramatically enhances corrosion resistance and mechanical durability.

5. Appearance & Dimensional Inspection Standards

Manual Inspection with Micrometer/Caliper:
Ensures dimensional accuracy per design specification.

Visual Inspection:
Performed under standard lighting to detect cracks, surface defects, or imperfections.

2D Optical Measurement System:
Used for irregular or complex-shaped parts to verify geometric and dimensional accuracy

Magnetic Flux Testing:
Ensures consistent magnetic strength across each production batch.

6. Reliability Testing

Drop and Vibration Testing:
Simulates transportation and operational impact to verify product reliability in end-use conditions.

High-Temperature Demagnetization Test:
Confirms thermal stability by measuring magnetism retention under high temperatures.

Damp Heat Test:
Evaluates resistance to corrosion and humidity in moisture-rich environments.

7. Packaging & Transportation

Defect Sorting:
Visual and dimensional defects are removed before final packing

Magnetizing & Arranging:
Each magnet is uniformly magnetized and packed as per customer requirements.

Vacuum Packaging:
Prevents moisture and magnetic interference during shipping and storage.

Outer Packaging:
Shock-resistant, moisture-proof, and anti-magnetic interference packaging ensures safe transportation.

8. Application Fields

Industrial Automation:
Fixtures, jigs, robotic arms — countersunk holes allow secure screw mounting for accurate positioning.

Tools & Equipment:
Positioning of electric tool components; removable magnetic covers for instruments.

Sensors & Detection Devices:
Magnetic sensors, reed switches, and position detectors.

Medical & Electronic Devices:
Mounting of portable medical devices and electronic modules — strong, stable force without interfering with sensitive electronics.

9. Usage Precautions

Handling:
NdFeB magnets are hard yet brittle—avoid dropping, collision, or edge impact.

Safe Operation:
Strong magnetic force may cause pinching—slide magnets apart instead of forcing them.

Proper Installation:
Identify and align polarities correctly to ensure stable operation.

Storage Conditions:
Avoid high temperatures, humidity, and corrosive (acid/alkali) environments.

Magnetic Interference:
Keep magnets away from sensitive equipment like hard drives, IC cards, and pacemakers.

10. Customization & Services

Customized dimensions, shapes, coating layers/thickness/color

Magnetic polarity and force specification

Laser engraving for logos or serial numbers

Encapsulation solutions and pull-force testing for specialized applications

11. Why choose Jinconn magnet / what jinconn offers

11.1Company Introduction

The company operates across a wide range of business areas, including the research, development, production, sales, and technology transfer of magnets and magnetic products. It also engages in the sales of hardware products, plastic components, electronic devices, and mechanical equipment, as well as import and export of goods and technologies.

As a National High-Tech Enterprise, a “Specialized and Sophisticated SME” of Guangdong Province, and a nationally recognized “Little Giant” enterprise, Jinkun New Materials possesses strong technological capabilities. To date, the company has filed 150 patent applications, including 3 international patents. These intellectual property achievements have significantly strengthened the company’s technological barriers and laid a solid foundation for its competitive position within the industry.

If you require samples, technical datasheets, or certifications such as MSDS, RoHS, ISO 9001, QC080000, IATF 16949, ISO 14001, or ISO 27001, our sales engineers are ready to assist you.