What are Alnico Cylinder Magnets?
Alnico cylinder magnets are cylindrical-shaped permanent magnets made from a premium alloy of aluminum, nickel, cobalt and iron, with optional trace metals for optimized magnetic performance. As a classic non-rare earth magnetic material, their cylindrical design is one of the most widely used forms for industrial applications, featuring uniform radial magnetic field distribution and perfect compatibility with rotating mechanical components like motor shafts and sensor rotors.
Unlike other magnet types, Alnico cylinder magnets retain their magnetic strength even in extreme temperature fluctuations (-250°C to 425°C) and harsh working environments, with a high Curie point of 850°C. They combine natural corrosion resistance, high magnetic permeability and easy assembly, making them an irreplaceable choice for high-temperature, high-precision industrial scenarios that demand stable and long-lasting magnetic performance.
Technical Advantages of Alnico Cylinder Magnets
Exceptional Thermal Stability: Alnico has the lowest temperature coefficient of any permanent magnet material. It can operate in temperatures as high as 550°C with negligible reversible loss, ensuring precision in extreme heat.
Superior Corrosion Resistance: Due to its metallic composition, Alnico is highly resistant to rust and corrosion. Most Alnico cylinder magnets require no plating or coating, though we offer painted or chrome finishes for aesthetic or identification purposes.
High Residual Induction (Br): While their coercivity is lower than rare-earth magnets, Alnico 5 and Alnico 8 grades offer high flux density, making them perfect for specialized sensor applications.
Precision Manufacturing: We offer both Cast Alnico (for complex shapes and high magnetic energy) and Sintered Alnico (for superior mechanical strength and tighter tolerances).
Material Composition & Performance
Alnico cylinder magnets’ superior performance is determined by its scientific alloy proportion, each element serving a critical role in optimizing magnetic and physical properties:
Aluminum (Al): Enhances corrosion resistance and mechanical hardness of the magnet
Nickel (Ni): Boosts magnetic stability and oxidation resistance, improves high-temperature performance
Cobalt (Co): Increases magnetic strength and energy density, expands the operating temperature range
Iron (Fe): Provides the basic magnetic performance, improves the alloy’s machinability
The adjustable alloy ratio allows for customized magnetic properties (remanence, coercivity) to meet the specific needs of different industrial applications, balancing magnetic strength and temperature resistance for optimal performance.
Cast vs Sintered Alnico Cylinder Magnets
We offer two mature manufacturing processes for Alnico cylinder magnets, each tailored to different application scenarios:
| Properties | Cast Alnico Cylinder Magnets | Sintered Alnico Cylinder Magnets |
| Dimensional Accuracy | Moderate, secondary machining required | High, tight tolerance for precision parts |
| Size Range | Suitable for large/over-sized cylinders | Ideal for small/miniature cylinder magnets |
| Shape Flexibility | Complex cylindrical shapes available | Standard cylindrical shapes, high consistency |
| Magnetic Performance | Higher remanence and energy density | Slightly lower magnetic performance, more uniform |
| Machinability | Good, easy for secondary processing | Brittle, requires precision grinding |
| Ideal Applications | Large motors, industrial generators, heavy equipment | Precision sensors, small actuators, mini instruments |
Magnetization Directions
Alnico cylinder magnets support magnetization directions optimized for their cylindrical structure, matching different magnetic circuit designs:
Axial Magnetization: Magnetic field along the central axis of the cylinder (most common for Alnico cylinder magnets)
Radial Magnetization: Magnetic field radiates from the center to the outer circumference, ideal for rotating motors
Custom Magnetization: Tailored magnetization according to specific industrial magnetic circuit requirements
Shape Categories of AlNiCo Magnet
Beyond the classic cylindrical design, AlNiCo magnets are engineered in a diverse range of precision shapes to match the unique magnetic circuit requirements of industrial, aerospace, automotive and precision instrument applications. Each shape is crafted for optimal magnetic field distribution, easy integration and reliable performance in high-temperature and harsh working environments, available in both cast and sintered formulations with customizable dimensions. Below are four core AlNiCo magnet shapes tailored for diverse use cases:
AlNiCo Bar Magnets
AlNiCo bar magnets feature a long, straight rectangular design with uniform magnetic performance along their length. Characterized by linear magnetic field distribution and high structural stability, they are ideal for applications requiring extended magnetic coverage and easy mounting—such as magnetic sensors, educational equipment, industrial gauges and linear motion systems. Their rigid bar structure ensures durable performance under vibration and mechanical stress, with customizable lengths and thicknesses to fit compact and large-scale design needs.
AlNiCo Block Magnets
AlNiCo block magnets (cube/rectangular prism) deliver a concentrated, consistent magnetic field across their flat surfaces, making them one of the most versatile AlNiCo shapes for industrial integration. With precise dimensional tolerance and high magnetic permeability, they are perfect for static magnetic circuits, magnetic clamping systems, precision instruments and heavy-duty industrial equipment. Available in custom block sizes (length, width, height), they offer flexible assembly options for both surface-mount and embedded design applications, retaining stable performance at extreme temperatures up to 425°C.
AlNiCo Horseshoe Magnets
AlNiCo horseshoe (U-type) magnets are designed with a curved, U-shaped structure that concentrates magnetic flux between the two pole ends, creating a strong, focused magnetic field for pick-up and holding applications. This iconic shape maximizes magnetic force in a compact form, making it ideal for hand tools, magnetic clamps, lifting equipment and educational demonstrations. Crafted for high mechanical strength and corrosion resistance, AlNiCo horseshoe magnets require no additional coating for most use cases and deliver long-lasting holding power in industrial and workshop environments.
AlNiCo Ring Magnets
AlNiCo ring magnets (annular design) feature a central bore with magnetic field distribution optimized for radial or axial magnetization, perfectly suited for rotating machinery, motor rotors/stators and magnetic coupling systems. Their axisymmetric structure ensures seamless integration with shafts and cylindrical components, providing stable magnetic performance in high-speed and high-temperature rotational applications—such as aerospace actuators, automotive sensors, precision motors and audio equipment. Customizable outer diameter, inner diameter and thickness allow for a perfect match with specific rotational magnetic circuit designs.
All AlNiCo magnet shapes share the core advantages of extreme temperature stability, natural corrosion resistance and high demagnetization resistance, with each form engineered to unlock optimal magnetic performance for its intended application. We offer full customization for all shapes, including dimensional tolerance, alloy grade and magnetization direction, to provide one-stop magnetic solutions for your unique design requirements.
