Direct sourcing portfolio of advanced NdFeB solutions optimized for tight-tolerance mechanical assemblies.
Founded in 1999, Zhejiang Laysun Magnetics Ltd. has systematically built its status as a cornerstone of advanced magnetic solutions. Spanning over two decades of technical evolution, the company is designated as a National High-Tech Enterprise in China. Our integrated model bridges the gap between fundamental research and mass-scale commercialization of Neodymium Iron Boron (NdFeB) material structures.
Operated from our expansive 100,000 m² state-of-the-art facility in Suining, Sichuan, we leverage local resource stability and advanced automated machining systems to yield a consistent 5,000 tons of rare earth magnets annually. This massive scale ensures that demanding global OEMs receive micro-level design consistency and reliable container-level output.
We believe in empowering next-generation clean energy, mobility, and computational hardware. By aligning our custom slicing capabilities with rigorous quality gates (including ISO 9001 and IATF 16949 standards), we enable smart device designers to push the thermal and magnetic limit of their applications.
Comprehensive physical, mechanical, and electromagnetic breakdown of the industry-standard disc profile.
The cylindrical disc measuring 20mm in diameter by 5mm in thickness (aspect ratio of 4:1) represents an engineering "sweet spot". In electromagnetic design, this proportions-ratio offers exceptional self-demagnetization resistance (load line operating point, PC ≈ 2.2) when magnetized axially. This renders it highly stable against ambient fields and temperature fluctuations compared to thinner profiles, maximizing operational reliability in dynamic load settings.
Depending on the operating environment of your product, selecting the appropriate NdFeB grade is vital. General applications utilize N Series (max operating temp: 80°C), while performance-critical sectors require higher coercivity grades like M Series (100°C), H Series (120°C), SH Series (150°C), UH Series (180°C), EH Series (200°C), or AH Series (220°C). We adjust the dysprosium (Dy) and terbium (Tb) heavy rare earth dopants to maintain maximum magnetic flux stability under severe heat stresses.
| Material Grade | Remanence (Br) | Coercivity (Hcb) | Intrinsic Coercivity (Hcj) | Max Energy Product (BH max) | Max Working Temp |
|---|---|---|---|---|---|
| N35 | 1.17 - 1.22 T (11.7 - 12.2 kG) | ≥ 868 kA/m (10.9 kOe) | ≥ 955 kA/m (12.0 kOe) | 263 - 287 kJ/m³ (33 - 36 MGOe) | 80 °C (176 °F) |
| N42 | 1.29 - 1.32 T (12.9 - 13.2 kG) | ≥ 923 kA/m (11.6 kOe) | ≥ 955 kA/m (12.0 kOe) | 318 - 342 kJ/m³ (40 - 43 MGOe) | 80 °C (176 °F) |
| N52 (Highest Flux) | 1.43 - 1.48 T (14.3 - 14.8 kG) | ≥ 820 kA/m (10.3 kOe) | ≥ 875 kA/m (11.0 kOe) | 398 - 422 kJ/m³ (50 - 53 MGOe) | 80 °C (176 °F) |
| N38SH (Motor Optimized) | 1.22 - 1.25 T (12.2 - 12.5 kG) | ≥ 907 kA/m (11.4 kOe) | ≥ 1592 kA/m (20.0 kOe) | 287 - 310 kJ/m³ (36 - 39 MGOe) | 150 °C (302 °F) |
| N35EH (Extreme Thermal) | 1.17 - 1.22 T (11.7 - 12.2 kG) | ≥ 875 kA/m (11.0 kOe) | ≥ 2388 kA/m (30.0 kOe) | 263 - 287 kJ/m³ (33 - 36 MGOe) | 200 °C (392 °F) |
Watch our automated manufacturing line and inspect our globally accepted quality credentials.
Our rare earth magnet products meet strict safety, quality, and environmental regulations required by aerospace, medical, and automotive markets.
How industries leverage this exact dimension to power modern tech, from mobile rings to electric drives.
Electric Power Steering (EPS) systems demand extremely reliable field strength. 20x5mm magnets, when arrayed inside brushless rotor shafts, provide the torque-to-inertia ratio needed for smooth driver assistance and emergency lane-keeping controls.
With highly precise thickness tolerances (±0.02mm), these disc magnets form the permanent magnetic gap inside VCM drives for high-accuracy laser focusing assemblies, fluid valve positioners, and optical stabilization modules.
Used inside consumer phone rings and alignment couplers. The 20x5mm footprint provides robust shear force to hold units together securely through casing layers, ensuring high induction efficiency and preventing misalignment during power transfers.
Why OEM buyers partner with Zhejiang Laysun to minimize raw material volatility and secure tariff-optimized delivery.
China controls a major share of the global rare earth extraction, refinement, and metallic processing supply chain. Our factory is strategically integrated near mining regions in Southwest China, which helps insulate us from fluctuations in NdFeB raw oxide pricing.
This geographic position ensures that Zhejiang Laysun has direct access to high-purity Neodymium (Nd), Praseodymium (Pr), Dysprosium (Dy), and Terbium (Tb). This ensures stable material pricing for our long-term contract partners, even during periods of global supply chain volatility.
Equipped with advanced wire slicing machines, multi-axis grinders, and automated nickel/epoxy electroplating facilities, we eliminate third-party processing overheads. Your custom 20mm x 5mm magnets are sliced, chamfered, coated, and inspected inside a single manufacturing ecosystem. This keeps our production costs lower than regional distributors and middlemen.
Pure chemical elements are melted in high-frequency induction furnaces to cast the alloy phase.
Alloy ingots are pulverized under hydrogen gas flow into ultra-fine micro-powders (3-5 microns).
Powder is aligned under multi-Tesla electromagnets and compressed into high-density green blocks.
How we verify and document every batch of custom 20mm x 5mm NdFeB magnets.
Every delivery includes a detailed Material Test Report (MTR), demagnetization curve analysis, and Salt Spray test validation certificates. Our QC labs are equipped with:
We supply materials compliant with European Union REACH directives, RoHS standards, and clean sourcing conflict mineral declarations. This direct factory accountability helps OEMs confidently pass audits by regional environmental agencies and safety authorities.
Understanding cost breakdowns and volume-based price incentives directly from the manufacturing source.
Neodymium pricing fluctuates based on global rare earth metal market values. Large-scale procurement contracts (100,000+ units) can be structured with formula-based pricing tied to index updates. This transparency helps mitigate risk for OEM budget planning.
Standard axially-magnetized N35 disc magnets serve as our pricing baseline. Additional design considerations include:
*The pricing below is an estimate for standard Ni-Cu-Ni plated N35 axially-magnetized 20mm x 5mm discs. Actual pricing varies based on raw material market rates.
In-depth technical answers addressing common manufacturing, coating, and application questions.
For high-humidity or corrosive environments, we recommend a Dual-Layer Epoxy or Parylene coating. Standard Nickel-Copper-Nickel (Ni-Cu-Ni) plating provides good protection in dry indoor settings but is porous and can fail under sustained humidity. Epoxy coatings seal the magnet material completely, providing up to 96 hours of salt spray resistance (under ISO 9227 standards). For critical applications like medical implants or marine sensors, Parylene provides pinhole-free barrier protection, chemical inertness, and biocompatibility, though at a higher cost.
An N52 grade magnet has a maximum operating temperature of 80°C (176°F). As temperature increases toward this limit, the magnet experiences a temporary loss in magnetic field strength (governed by a temperature coefficient of Br at roughly -0.11% per °C). If this threshold is exceeded, the magnetic flux loss becomes permanent. If your application operates at higher temperatures, we recommend switching to High-Temperature grades like N42SH (up to 150°C) or N38UH (up to 180°C), which incorporate dysprosium to resist demagnetization under heat.
Our standard manufacturing tolerance for sintered Neodymium disc magnets is ±0.05mm on both diameter and thickness. Using our advanced grinding and slicing equipment, we can achieve precision tolerances of ±0.02mm for applications requiring high precision. These tight tolerances are essential for voice coil motors, automated sensor housings, and robotic arms, where minor dimensional variances can cause mechanical interference or magnetic imbalances.
Axial magnetization means the magnetic poles are located on the flat circular faces of the disc (the north pole on one flat side and the south pole on the other). This is the standard configuration for holding applications, sensors, and MagSafe rings. Radial magnetization means the poles are oriented through the outer edges of the diameter (one half of the curved outer edge is north, and the opposite is south). Radial magnetization is generally more complex and is typically used in specialized electric motors, rotary encoders, and actuator assemblies.
Explore our wider inventory, including custom blocks, rings, and heavy lifting magnetic assemblies.
Whether you require a custom grade, unique coating, or high-volume pricing for 20mm x 5mm Neodymium Magnets, submit your email address below. Our technical sales engineers will respond with a detailed quote within 24 hours.
Laysun Magnetics
