SMON6921 1/4 x 1/8 Inch Neodymium Rare Earth Epoxy Coated Disc Magnet N42

Brand Description

Stanford Magnets, a company specializing in the research and production of advanced materials, guarantees that each of its products reaches international leading standards through meticulous craftsmanship and strict quality control. The 1/4 x 1/8 Inch Neodymium Rare Earth Epoxy Coated Disc Magnet N42 delivers exceptional magnetic strength (42 MGOe) and robust corrosion resistance for cost-sensitive industrial, electronic, and DIY applications.

Related Products: Plastic Coated Magnets

1/4 x 1/8 Inch Neodymium Rare Earth Epoxy Coated Disc Magnet N42 Specifications

Properties

*The above product information is based on theoretical data. For specific requirements and detailed inquiries, please contact us.

1/4 x 1/8 Inch Neodymium Rare Earth Epoxy Coated Disc Magnet N42 Description

The Neodymium Rare Earth Epoxy Coated Disc Magnet N42 is fabricated from sintered neodymium-iron-boron (NdFeB), achieving a maximum energy product of 42 MGOe. Measuring 6.35 mm (0.25") in diameter and 3.18 mm (0.125") in thickness, it features a uniform epoxy coating (20–30 μm) that provides superior resistance to humidity, chemicals, and mechanical abrasion, extending service life in harsh environments. The magnet is axially magnetized, generating a surface field of ≥3,900 Gauss and a pull force of ≥1.8 kg. Its thermal stability is characterized by a Curie temperature of 310°C, with irreversible flux loss occurring above the maximum operating temperature of 80°C. The epoxy layer enhances electrical insulation and mitigates brittleness-related chipping during handling. With a density of 7.5 g/cm³ and tight dimensional tolerances (±0.05 mm), it ensures consistent performance in precision assemblies.

1/4 x 1/8 Inch Neodymium Rare Earth Epoxy Coated Disc Magnet N42 Applications

Electronics: Vibration motors in wearables, sensors in IoT devices, and magnetic latches for laptops.

Industrial: Encoders, limit switches, and magnetic couplings in automation equipment.

Renewable Energy: Rotor positioning in small-scale wind turbines.

Consumer Goods: Cabinet closures, tool holders, and craft projects (e.g., with adhesive backing).

Automotive: Position sensors and dashboard component retention.

1/4 x 1/16 Inch Neodymium Rare Earth Gold Plated Disc Magnet N52 Packaging

To ensure safety during transportation and compliance with shipping regulations, all magnets are securely packed with a metal shielding layer inside the box. This prevents magnetic interference with surrounding items and protects the product from external damage.

Packaging: Carton, Wooden Box, or Customized.

1/4 x 1/8 Inch Neodymium Rare Earth Epoxy Coated Disc Magnet N42 FAQs

Q1. Why choose N42 over higher grades like N52?

N42 balances cost and performance, ideal for applications not requiring extreme flux density. N52 offers ~20% higher strength but increases cost by 30–50% and is less thermally stable.

Q2. How does epoxy coating compare to nickel plating?

Epoxy provides better insulation and impact resistance but lower corrosion protection than nickel in acidic environments. Use epoxy for electrical isolation and in damp conditions.

Q3. Will exposure to >80°C permanently weaken the magnet?

Yes. Temperatures exceeding 80°C cause irreversible demagnetization. For high-temp applications (>100°C), consider grades like N42H or N42SH.

Related Information

1. Common Preparation Methods

Neodymium magnets are manufactured via powder metallurgy. Neodymium, iron, and boron raw materials are melted in a vacuum induction furnace at >1,300°C, cooled into ingots, and milled into 3–5 μm particles. The powder is compacted under a 1.5–2 T magnetic field to align crystal orientations, then sintered at 1,080–1,100°C in argon to achieve >99% density. Sintered blocks are annealed to optimize coercivity, machined to precise dimensions using diamond-grinding tools, and cleaned ultrasonically. Epoxy coating is applied by electrostatic spraying or fluidized bed deposition, followed by curing at 150–180°C for 30–60 minutes. Finally, magnets are axially magnetized in a >3 T pulsed field and tested for flux uniformity using Helmholtz coils.