Black ferrite block magnet, also known as permanent ferrite square magnet, is a traditional and cost-effective rigid permanent magnet material made of strontium ferrite or barium ferrite as the main raw material, through batching, ball milling, pressing, high-temperature sintering and grinding molding. The product presents uniform black appearance, with regular block and square structure, smooth surface and stable physical and chemical properties. As one of the most mature permanent magnet materials in the industry, black ferrite block magnets have the advantages of low cost, high stability, strong corrosion resistance and long service life, and occupy an important position in the middle and low-end permanent magnet application market. Unlike NdFeB magnets, ferrite block magnets do not contain rare earth elements, so the price is stable and cost-effective, suitable for large-scale industrial batch use and civilian conventional magnetic products.

In terms of magnetic performance, black ferrite block magnets have stable and reliable magnetic output. The conventional magnetic grades are Y30, Y35, Y40 and other mainstream grades, with a magnetic energy product of 2.8–4.2 MGOe, moderate magnetic force, no sudden magnetic attenuation in long-term use, and excellent magnetic stability. The product has excellent demagnetization resistance, and it is not easy to demagnetize under the interference of external magnetic field, vibration and temperature change, which ensures the long-term stable operation of equipment. In terms of mechanical properties, the block structure has high structural rigidity, good compression resistance and deformation resistance, and can withstand large external pressure without deformation. After fine grinding treatment, the size of the block magnet is accurate, the edge is smooth without burrs, and the flatness and verticality of the square surface are high, which is convenient for precise assembly and fixed installation. The product supports customized processing of various specifications, with adjustable length, width and thickness, and can be made into standard square blocks, rectangular blocks and special-shaped blocks according to user requirements.

Black ferrite block magnets have outstanding environmental adaptability and durability. The material itself has natural anti-corrosion, anti-rust and anti-oxidation properties, no need for complex surface electroplating and coating treatment, and can work stably in humid, dusty and ordinary corrosive environments for a long time. The working temperature range is -20°C to 120°C, with good high-temperature resistance, no demagnetization or deformation in high-temperature working environment, and better temperature stability than ordinary rubber soft magnets. The product has strong aging resistance, and its magnetic performance and structural stability can be maintained for more than 10 years in natural environment, with extremely low maintenance cost. In addition, ferrite magnets are non-toxic, environmentally friendly, non-radiative, compliant with international environmental protection standards, safe and harmless to human body and environment, and can be widely used in civilian products and food-related equipment accessories.

The application fields of black ferrite block magnets are very extensive, covering civilian life, industrial manufacturing, electronic electrical and other multiple fields. In the electrical industry, they are used for stator and rotor magnetic parts of small motors, fan motors, water pump motors and household appliance motors, providing stable magnetic field for motor operation. In the mechanical fixing field, they serve as magnetic fixing blocks for equipment tooling, magnetic base accessories, mechanical positioning magnetic parts and iron workpiece adsorption fixing components. In the daily civilian field, they are applied to magnetic accessories of household appliances such as refrigerators, washing machines and air conditioners, magnetic fixing parts of fitness equipment, and magnetic components of toys and handicrafts. In the industrial filtration field, they are made into magnetic filter blocks, used for removing iron impurities in industrial materials, purifying production raw materials. In addition, they are also widely used in automobile accessories, security equipment, lighting equipment, teaching experimental equipment and other fields. Due to their ultra-high cost performance, stable performance and wide adaptability, black ferrite block magnets have always been the mainstream basic magnetic materials in the permanent magnet industry, with stable and lasting market demand.