High-Performance Ring-Shaped Neodymium Magnet

1. Product Overview

This is a high-performance ring-shaped neodymium magnet with N52 grade, featuring extremely high magnetic strength, excellent demagnetization resistance, and precise dimensional accuracy. The product's precision can be customized according to customer requirements. Its sophisticated ring-shaped design meets high-performance magnetic needs in compact spaces, making it widely applicable in high-end electronic devices, audio equipment, premium perfume bottle caps, and other fields.

The magnet is manufactured using advanced wire cutting, centerless grinding, and double-disc grinding processes, ensuring neat edges and uniform dimensions. Surface treatment includes multi-layer metal coating (Ni+Cu+Ni) or optional Zn coating, effectively preventing oxidation and corrosion from environmental factors, thereby extending the product's service life.

2. Technical Specifications

Product Name: Ring-shaped high-performance rare earth neodymium magnet

Material Grade: N52 (Br ≥ 14.2 kGs, Hcj ≥ 12 kOe)

Dimensions: D20-D17×2 mm (custom sizes available)

Dimensional Tolerance: ±0.05 mm (length/width/thickness)

Operating Temperature: ≤80℃ (high-temperature versions customizable)

Density: ≥7.5 g/cm³

Surface Magnetic Field: 3000 ± 200 Gauss (measured with Japanese TM-801 Gauss meter)

Magnetic Flux Value: 2.1 mWb (measured with fluxmeter)

3. Manufacturing Process

The product is manufactured through the following key processes:

• l Wire Cutting: Uses molybdenum/copper wire cutting equipment to achieve ±0.02mm precision for small-batch custom rings.

• l Centerless Grinding: Refines inner and outer diameters to ensure roundness (±0.05mm tolerance).

• l Double-Disc Grinding: Controls thickness and parallelism.

4. Surface Treatment and Coating Technology

To enhance corrosion resistance and appearance quality, the following surface treatment solutions are adopted:

• Default Coating: Triple-layer nickel-copper-nickel (Ni-Cu-Ni). Coating can be customized according to customer requirements.

• Coating Thickness Standard: Ni (3μm) + Cu (5μm) + Ni (4μm). Coating thickness can be customized as needed.

• Optional Coating: Single-layer zinc (Zn 5μm) for cost-sensitive projects.

Coating Features:

• Resistant to salt spray corrosion and improved oxidation resistance.

• Increased surface hardness to prevent scratches.

• Enhanced appearance glossiness, suitable for exposed components.

5. Appearance and Dimensional Inspection Standards

To ensure consistent and reliable product quality, all products undergo the following inspection processes:

Manual dimensional inspection with micrometers/calipers.

Visual inspection (under 800-1200 lumen lighting at 20-30 cm standard inspection distance).

2D image measurement for precise dimensional verification.

Automated CCD sorting and full inspection of product appearance and dimensions.

Magnetic flux testing to ensure batch consistency of magnetic performance.

6. Reliability Testing

• Neutral Salt Spray Test (NSS):

Temperature: 35℃ ±2℃

Salt spray deposition rate: 1~2 ml / 2000px²·h

pH value: 6.5 ~ 7.2

Test duration: 24h / 48h / 72h / 96h (can be set according to application scenarios/customer requirements).

• Thermal Demagnetization Test:

Placed in a constant-temperature oven (80℃) for 2 hours (test duration can be adjusted per customer requirements).

Demagnetization rate ≤10% is considered qualified.

Simulates thermal stability in real-world applications.

• Drop Test Notice:

This product is not suitable for drop tests as neodymium magnets are brittle and strong impacts may cause chipping or cracking.

 

7. Packaging Process and Instructions

In compliance with magnetic product transportation requirements, we implement professional packaging methods:

• Defective items in appearance and dimensions are removed.

• Qualified products are uniformly magnetized and neatly arranged.

• Customized box quantities and labels per customer requirements.

• Each box is vacuum-packed with magnetic shielding plates and shock-absorbing pads.

• Small boxes are packed into master cartons with moisture, impact, and magnetic interference protection.

Packaging methods can be customized.

8. Application Fields

This product is widely used in:

• Smart wearable devices: Magnetic structures for smart bands, earbud positioning, electric toothbrush chargers.

• Audio equipment: Speaker and headphone magnetic circuits (Hi-Fi systems, TWS earbuds).

• Industrial applications: Motor cores, sensors, braking systems in power tools.

9. Usage Precautions

• Handle with care: Neodymium magnets are brittle—avoid impacts or drops.

• Avoid pinching: Always slide magnets apart instead of pulling directly.

• Store properly: Keep away from high temperatures, humidity, and corrosive environments.

• Safety warning: Keep strong magnets away from electronic devices, credit cards, and medical implants like pacemakers.

10. Customization and Services

We support various customization services:

• Size, shape, and coating (layer count, thickness, color) customization.

• Polarity direction and magnetic strength adjustment.

• Laser-engraved logos or serial numbers.

• Special application packaging solutions and pull-force testing support.

If you need any solution for your mobile, speaker or robotics project technical data sheet，please feel free to contact our sales engineers, we are always ready to assist you!