Ferrite Magnet (18X4)

About Ferrite Magnet (18X4)

An 184 ferrite disc magnet is a cylindrical permanent magnet with a diameter of 18 millimeters and a thickness of 4 millimeters, manufactured from ceramic ferrite material, most commonly strontium ferrite (SrFeO) or, in some cases, barium ferrite (BaFeO). These magnets are widely used because they offer a reliable balance of moderate magnetic strength, excellent chemical stability, temperature resistance, and low cost.

Material and Composition

The 184 ferrite disc magnet is classified as a hard ceramic magnet. It is produced through a powder metallurgy process in which finely milled iron oxide is mixed with strontium or barium carbonate. This powder blend is pressed into a disc shape and then sintered at high temperatures (approximately 12001300C). During sintering, a dense ferrite crystal structure forms, giving the magnet its permanent magnetic properties.

The final magnet is typically dark gray to black in color with a matte or semi-smooth surface finish. Ferrite magnets usually do not require protective coatings because they are naturally resistant to corrosion, moisture, and most chemicals.

Key Characteristics

Magnetic Properties

• Permanent magnet that does not require a power supply

• Moderate magnetic strength compared to rare-earth magnets

• High coercivity, providing good resistance to demagnetization

• Typically axially magnetized, though radial magnetization is also possible for specific applications

Mechanical Properties

• Hard and wear-resistant

• Brittle in nature; can chip or crack if subjected to impact or sudden shock

• Dimensionally stable under normal operating conditions

Thermal and Chemical Properties

• Excellent resistance to corrosion, humidity, oils, acids, and alkalis

• Electrically insulating, suitable for electronic and electrical assemblies

• Can operate reliably at temperatures up to ~250C, with minimal loss of magnetic performance

• Advantages

  • Cost-effective compared to neodymium and other rare-earth magnets

  • Naturally corrosion-resistant with no need for plating

  • Stable magnetic performance over long service life

  • Suitable for high-temperature and harsh environments

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  Summary:
  The 184 ferrite disc magnet is a durable, corrosion-resistant, electrically insulating permanent magnet designed for applications that require reliable, moderate magnetic force and long-term stability rather than maximum strength. Its size makes it especially useful in industrial, electrical, and general-purpose magnetic assemblies where robustness and cost efficiency are important.