Custom Samarium Cobalt Magnets (SmCo)

Samarium cobalt magnets are rare-earth permanent magnets composed of samarium and cobalt alloys, available since the early 1970s and still among the most technically capable magnetic materials in use today. SmCo magnets combine very high magnetic energy output with exceptional thermal stability and natural resistance to corrosion, making them the preferred choice for applications where neodymium magnets would fail due to temperature, oxidation, or corrosive exposure.

Magnetic Hold is a custom samarium cobalt magnet manufacturer offering SmCo magnets in a full range of grades, shapes, and custom dimensions for industrial, aerospace, defense, medical, and marine applications.

Properties and Advantages of Samarium Cobalt Magnets

SmCo magnets are manufactured by sintering or compression bonding and are anisotropic—meaning they can only be magnetized in the direction of orientation. The material magnetizes readily along its preferred axis but resists magnetic pull in all other directions, which is a critical feature in precision sensor and motor applications.

Key properties that distinguish samarium cobalt magnets from other permanent magnet materials:

• High Maximum Operating Temperature — SmCo magnets maintain stable performance up to 300°C (572°F) depending on grade, far exceeding the practical limits of standard neodymium magnets
• Excellent Corrosion Resistance — Unlike neodymium, SmCo magnets do not require a protective coating for most environments, making them well-suited for marine, chemical, and outdoor applications
• Very High Coercivity — SmCo resists demagnetization better than most other materials, preserving magnetic performance in high-field and high-temperature environments
• Low Temperature Coefficient — The magnetic output of SmCo changes minimally across a wide temperature range, which is critical for precision instruments and sensors
• Long-Term Stability — SmCo magnets retain their magnetism reliably over decades, reducing replacement costs in demanding installations

We can provide custom shapes and sizes of samarium cobalt magnets by working with you to create your unique specifications. Some of the different shapes include:

• Arc
• Bar
• Rod
• Disc
• Horseshoe
• Channel
• Block
• Ring
• Sphere
• Cylinders
• Plugs
• Cube

Applications of Samarium-Cobalt Magnets

SmCo magnets are used wherever standard magnets cannot reliably perform. Their combination of high-temperature stability, corrosion resistance, and strong coercivity makes them the material of choice for high-reliability programs.

Common Industries That Use Samarium-Cobalt Magnets

• Aerospace — onboard sensors, actuators, and positioning systems exposed to temperature extremes

• Defense / Military — munitions guidance systems, ruggedized equipment, and field-deployed electronics
• Medical — MRI-adjacent equipment, implantable devices, surgical instruments, and precision medical sensors
• Automotive — high-temperature motor and sensor applications within powertrain and EV systems
• Marine — underwater motors, navigation instruments, and equipment exposed to salt water and humidity
• Food Processing — separation and contamination control in high-temperature processing lines
• Manufacturing — motors, generators, and couplings in industrial equipment

Common Applications for Samarium-Cobalt Magnets

• Electric motors and generators requiring high-temperature performance
• Precision sensors and transducers where stable output over temperature is critical
• Magnetic couplings in sealed or corrosion-exposed systems
• Magnetic separators in high-temperature food or chemical processing
• Cryogenic and vacuum applications where reliability and low outgassing matter
• Medical devices requiring long-term magnetic stability
• Military and aerospace electronics operating in wide thermal environments

Contact us or request a quote to find out how we can help you.

Magnetism Direction Options

We can offer several different magnetization directions, see below schematics. Their availability is limited to size. Magnetization fixture cost may apply for large and custom magnets with magnetization other than what is shown below

Cylinder Ring, Axial

Cylinder Ring, Diametrical

Cylinder, Axial

Cylinder, Diametrical

Disc Ring, Axial

Disc Ring, Diametrical

Disc, Axial

Disc, Diametrical

Rectangle, Axial

Rectangle, Length

Rectangle, Width

Segment Thru Circumference

Segment Thru Diameters

Segment Thru Thickness

The table below offers some guidelines for selecting a grade that will best suit your application.

Sintered Samarium Cobalt Magnets Grades & Properties

Br: Residual Induction
Gs: Gauss
Hc: Coercive Force
Oe: Oersted
˚C: Degree Celcius
MGOe: Mega Gauss Oersted

Standard Tolerances (inches);
All shapes and sizes (±0.005)

Safety Information for Handling SmCo Rare Earth Magnets

⚠️ Important: Samarium cobalt magnets are brittle rare earth materials that require careful handling. Magnets larger than a few centimeters generate sufficient attraction force to pinch body parts between two magnets or between a magnet and a ferrous surface—serious injuries including broken bones are possible. SmCo magnets that contact each other at speed can chip or shatter, and the resulting fragments can cause eye and skin injuries. Always handle SmCo magnets with appropriate PPE and keep them restrained during assembly.

Request a Quote for Custom Samarium Cobalt Magnets

Magnetic Hold is an ISO 9001:2015- and AS9100D-certified samarium cobalt magnet manufacturer. Whether you need a standard grade in a custom shape, a tight-tolerance prototype, or a full production run, our engineering and manufacturing team is ready to help.

Submit a quote request or contact us to discuss your SmCo magnet requirements.