High temperature-resistant permanent rare earth, rectangular 16mm x 8mm x 3mm (5mm hole) epoxy-plated countersunk magnet

Understanding Neodymium Magnets

These high-temperature-resistant, permanent, rare-earth, strong,  rectangular 16mm x 8mm x 3mm (5mm hole) epoxy-plated countersunk magnet 16mm x 8mm x 3mm (5mm hole) epoxy-plated countersunk magnets are known for their exceptional super-strong magnetism, making them the strongest type of permanent magnet on the market. Their compact size allows them to deliver high magnetic force even in space-constrained applications. In construction, they help securely position metal components during assembly, while in the medical sector, they play a vital role in the consistent performance of imaging systems and sensitive equipment. From everyday home tasks to demanding industrial operations, these magnets ensure dependable, long-lasting functionality.

16mm x 8mm x 3mm (5mm hole) epoxy-plated countersunk magnet

These high-temperature-resistant, permanent, rare-earth, strong,  compact, rectangular 16mm x 8mm x 3mm (5mm hole) epoxy-plated countersunk magnet 16mm x 8mm x 3mm (5mm hole) epoxy-plated countersunk magnets are designed for industrial applications, especially in making energy-efficient electric motors and generators. Their curved shape allows them to fit smoothly around the rotor, helping to create a strong and steady magnetic field. This improves motor performance and helps save energy. Commonly used in industries like automotive, robotics, and clean energy, these magnets support systems that need high torque and efficiency. They also play a key role in industrial machinery and automation, helping equipment run reliably and last longer, an important benefit for modern manufacturing.

Magnet Grade: N52

N52 neodymium magnets offer some of the strongest magnetic power available, with an energy rating of up to 52 MGOe. As one of the highest grades, they are ideal for projects that need extra-strong magnetism. Their powerful performance makes them a reliable choice for demanding applications where maximum strength is essential.

Surface Finish: Ni-Cu-epoxy 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 it 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

Material Neodymium (NdFeB)

Product Name: High temperature-resistant permanent rare earth, rectangular 16mm x 8mm x 3mm (5mm hole) epoxy-plated countersunk magnet
Magnetic Grade: N52 (Br ≥ 14.8 kGs, Hcj ≥ 12 kOe)
Dimensions: 16mm x 8mm x 3mm
Dimensional Tolerance: Length ±0.05mm, Width ±0.05mm, Thickness ±0.05mm
Operating Temperature: ≤80°C (high-temp version available)

Pull (kg): 1.31KG

Magnetisation Direction: Radially Magnetised
Density: ≥7.5 g/cm³
Surface Magnetic Field: 3800 ±200 Gauss (measured with TM-801 Gauss meter)
Magnetic Flux: 2.3 mWb (measured with fluxmeter)

Manufacturing Process 

The manufacturing process of this Precision customized strong magnetic force high energy density compact bore magnetic pot ndfeb magnet are as following:

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. 

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. 

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.

Reliability Testing

To ensure 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.

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

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.

 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.

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!

  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.

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.

Contact Us：

 Phone/WhatsApp/WeChat: +86 13829120676

 Email: Info@jinconn.com

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