Powerful D25mm x 4.5mm Round Neodymium – Nickel Coated, Disc Magnet

Powerful D25mm x 4.5mm Round Neodymium – Nickel Coated, Disc Magnet

2025-7-16

D25mm x 4.5mm Round Neodymium – Nickel Coated, Disc Magnet

These neodymium disc magnets offer a powerful and compact magnetic solution for home projects, including creating magnetic fixtures, organising tools, or securing lightweight items. In the professional world, they are crucial in manufacturing, engineering, and product design, where their magnetic strength and precision are essential for holding and positioning small components. Furthermore, they are used in the energy sector, particularly in the development of renewable energy devices, where their magnetic force contributes to efficient operation. These magnets are utilised across various industries, making them a reliable choice for both consumers and businesses.

Magnet Grade: N42

N42 grade neodymium magnets offer a balanced combination of strength and versatility, with a maximum energy product of around 42 MGOe. Well-suited for various applications including motors, sensors, and precision assemblies, they deliver consistent magnetic performance. Their reliable field strength makes them a preferred choice for consumer electronics and technical equipment alike. Widely adopted across industries, N42 magnets are valued for their dependable and efficient performance.

Surface Finish: Ni-Cu-Ni Coating

These magnets are finished with a durable triple-layer Ni-Cu-Ni (Nickel-Copper-Nickel) coating that enhances corrosion resistance and maintains a clean, professional look. This layered shield protects the magnet’s core from oxidation and wear in mildly humid environments, making them suitable for long-term use in a range of settings. For more aggressive environments, epoxy or other advanced coatings may offer enhanced protection.

APPLICATION EXAMPLES

Technical Parameters

Product Name: D25mm x 4.5mm Round Neodymium – Nickel Coated, Disc Magnet
Magnetic Grade: N42 (Br ≥ 13.5 kGs, Hcj ≥ 12 kOe)
Dimensions: D - 10x2mm (customizable)
Dimensional Tolerance: Length ±0.05mm, Width ±0.05mm, Thickness ±0.05mm
Operating Temperature: ≤80°C (high-temp version available)
Density: ≥7.5 g/cm³
Surface Magnetic Field: 2450 ±200 Gauss (measured with TM-801 Gauss meter)
Magnetic Flux: 2.3 mWb (measured with fluxmeter)

Manufacturing Process

The product is manufactured through the following key processes:

● A high-speed grinding wheel shapes the magnet's surfaces with tight dimensional tolerances.

● Coolant fluid is applied to control heat, reduce surface stress, and ensure a smooth finish.

● The result is a uniform, precisely dimensioned magnet with clean edges—ideal for high-performance applications.

This precision step is essential for ensuring that the final magnets meet strict quality standards for use in motors, sensors, electronics, and aerospace components     

Surface Treatment & Plating

To enhance corrosion resistance and appearance:

Default Plating: Triple-layer Ni-Cu-Ni (customizable).

Standard Thickness: Ni (3μm) + Cu (5μm) + Ni (4μm).

Optional Plating: Single-layer Zn (5μm) for cost-sensitive projects.

Features:

✔ Salt spray & oxidation resistance

✔ Increased surface hardness (scratch-resistant)

✔ Improved gloss (ideal for exposed components)

Appearance & Dimensional Inspection

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

Image Measurement System: High-res cameras and algorithms conduct non-contact 2D measurements, especially for complex or irregular shapes, ensuring efficiency and objectivity in mass production.

Reliability Testing

Impact & Vibration Test: Simulates shipping and usage conditions to ensure operational stability.

Constant Temperature & Humidity Test: Performed under 85°C and 85% RH for 96–500 hours. Performance and appearance are compared before and after testing.

Damp Heat Test: Evaluates resistance to high humidity and corrosion.

Applications

Electric Motors & Generators
Application: Precision-engineered magnets are employed in stators, rotors, and brushless DC motors to enhance magnetic flux density, efficiency, and torque performance.

Consumer Electronics
Application: High-performance neodymium magnets are integrated into speakers, haptic systems, vibration motors, and sensors, contributing to compact design and reliable functionality.

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 a tracking code

We understand logistics is more than just transport — it's about your commitment and customer satisfaction. Our solutions offer:

● Global logistics support

● End-to-end visual tracking

● Multiple layers of transport safety

● One-on-one customer service for tailored shipping plans

With our reliable land, sea, and air logistics network, we empower your business to go further and soar higher.

Frequently Asked Questions:

Q: How to choose the correct magnetization direction?

Axial Magnetization: Magnetic lines flow through the thickness — best for concentrated fields

Radial Magnetization: Magnetic lines radiate outward, for uniform field distribution

Multipole Magnetization: Multiple poles along circumference — for complex fields (e.g., motors, sensors)

Q: What is the maximum working temperature of a ring magnet?

Standard N-series: up to 80°C

High-temp grades (SH/UH/EH): up to 150°C–230°C

Dysprosium-enriched formulations can further enhance temperature resistance

Q: Does magnetism decay over time?

Under normal conditions (room temp, dry, no heavy vibration), NdFeB magnets exhibit excellent time stability (<5% loss over 10 years). However, factors like:

● Temperature overrun

● Strong external magnetic fields

● Surface corrosion

● Mechanical impact may affect performance.

Why Choose us ？

Dongguan Jinconn New Material Holdings 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. 

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.

Usage Precautions？

● Handle gently: Avoid impacts/drops (brittle material).

● Prevent pinching: Slide magnets apart—do not pry.

● Polarity check: Install correctly to avoid malfunctions.

● Avoid moisture/acids: Store in dry, mild environments.

● Keep away from sensitive devices: Hard drives, IC cards, pacemakers, etc.

Customization & Services

● Custom magnet size, shape, and coating (layers, thickness, color)

● Tailored magnetization direction and field strength

● Laser engraving service for logos or serial numbers

● Packaging and suction force testing for special applications

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

We’re here to help!

 Phone/WhatsApp/WeChat: +86 180 3822 5893
 Email: info@jinconn.com
 Website: www.jinconnmagnet.com
Address: Xiaohe Industrial Zone, Daojiao Town, Dongguan City, Guangdong, China