In these cases, SmCo arc magnets are usually selected for the operating condition and assembly structure, rather than as standard catalog magnets.
SmCo arc magnets are usually designed for specific assemblies rather than selected from standard magnet sizes. Their curved shape, segment angle, material grade, and arrangement are often decided by the assembly layout, available space, magnetic circuit, and operating condition.
This is different from many simple block, disc, or ring magnets. In arc-shaped magnetic assemblies, the magnet does not work alone. It works together with the air gap, steel parts, adhesive, sleeve, housing, and surrounding magnetic circuit. For this reason, the final performance depends on the complete assembly, not only on the magnetic properties of a single magnet segment.
Samarium Cobalt arc magnets are usually considered when the operating condition justifies SmCo material. In many room-temperature designs, Neodymium arc magnets may still be the first choice because of their high magnetic strength and wider availability. SmCo arc magnets become more relevant when temperature stability, resistance to demagnetization, corrosion resistance, or long-term reliability is more important than maximum room-temperature magnetic output.
For this reason, SmCo arc magnets should be reviewed as part of the magnetic assembly, not only as individual curved magnet pieces.
SmCo arc magnets are mainly used when the magnetic layout follows a circular or partially circular path. Instead of placing straight magnets around a curved structure with large gaps or poor contact, arc magnets can better match the shape of rotors and stators of permanent magnet motors, magnetic couplings, and other circular magnetic systems.
In these structures, each Samarium Cobalt arc magnet normally works as one segment of a larger magnetic circuit. The magnetic field is influenced by the number of segments, the air gap, the steel parts, the bonding method, and the surrounding mechanical structure. This is why arc magnets are usually evaluated together with the full assembly design.
For high-temperature or reliability-focused systems, SmCo arc magnets can be useful when the magnetic assembly must maintain stable performance under heat, reverse field influence, or long service conditions.
Samarium Cobalt arc magnets are made from a hard and brittle material, so the curved edges, thin ends, and bonding surfaces should be handled carefully during assembly. In many projects, arc magnets are fixed with adhesive, sleeves, housings, or steel backing structures. These surrounding parts can affect both mechanical reliability and magnetic performance.
Most practical SmCo arc magnets are magnetized in a straight direction across the segment rather than true radial magnetization. The magnetization direction should match the magnetic circuit and the way each segment is arranged in the circular structure. If the drawing assumes an ideal radial field, the actual magnet design and magnetization feasibility should be reviewed before production.
In high-speed or alternating-field systems, arc magnets may also be designed as laminated magnets to help reduce eddy current losses and related heat generation. This is not only a matter of dividing one magnet into thinner pieces. The laminated structure should be reviewed together with bonding strength, insulation between layers, magnetization direction, dimensional tolerance, and the final rotor or stator assembly.
Custom Samarium Cobalt arc magnets are normally made according to drawings, samples, or the structure of the final magnetic system. Their curved shape, segment size, and magnetization direction should match the circular layout where the magnets will be assembled.
The material grade should be selected according to the working temperature, magnetic output, and reliability requirements. For laminated arc magnets or arc magnets used with sleeves, housings, adhesives, or steel parts, the magnet design should also be reviewed together with the surrounding assembly.
SDM Magnetics supplies custom SmCo arc magnets for project-specific circular magnetic systems, including curved segments used in permanent magnet motors, magnetic couplings, and other magnetic structures.
