Samarium Cobalt Countersunk Ring Magnet – 20mm OD x 10mm H | 5.2mm Countersunk Hole | South on Countersunk Face

The Samarium Cobalt (SmCo) Countersunk Ring Magnet – 20mm OD x 10mm H with 5.2mm countersunk hole | South on Countersunk Face is a high-performance rare earth permanent magnet designed for demanding applications requiring reliable magnetic strength, excellent temperature stability and secure mechanical mounting.

Measuring 20mm outside diameter x 10mm high, this round SmCo magnet features a 5.2mm countersunk centre hole for installation using a compatible countersunk fastener. This version has a defined magnetic orientation with the South pole located on the countersunk face, making it particularly useful for engineered assemblies where precise and consistent polarity is required.

Samarium Cobalt magnets offer excellent resistance to elevated temperatures, corrosion and demagnetisation. These properties make SmCo a preferred magnetic material for specialised industrial, engineering, aerospace, automotive, sensing and high-temperature applications where conventional neodymium magnets may not provide the required environmental stability.

Key Features

• High-performance Samarium Cobalt (SmCo) rare earth magnet
• 20mm outside diameter
• 10mm height
• 5.2mm countersunk centre hole
• South pole on the countersunk face
• Defined polarity for precision magnetic assemblies
• Designed for secure countersunk screw mounting
• Excellent high-temperature performance
• High resistance to demagnetisation
• Naturally good corrosion resistance
• Suitable for demanding industrial and engineering applications

Common Applications

• High-temperature magnetic assemblies
• Industrial machinery
• Aerospace components
• Automotive equipment
• Sensors and instrumentation
• Magnetic positioning systems
• Motors and specialised electronics
• Scientific equipment
• Custom fixtures and mechanisms
• OEM magnetic assemblies

South Pole on the Countersunk Face

This SmCo magnet has a specified magnetic orientation with the South pole located on the countersunk face.

Defined polarity is particularly important for applications involving magnet-to-magnet attraction or repulsion, magnetic sensors, switching systems, positioning mechanisms and precision assemblies.

This South-pole version can also be paired with a compatible magnet that has its North pole on the corresponding mating face, creating an attractive magnet-to-magnet connection. Always verify polarity and installation orientation before permanently mounting the magnets.

Countersunk Hole for Mechanical Mounting

The 5.2mm countersunk centre hole provides a convenient method for mechanically securing the magnet to a suitable substrate.

Using an appropriately sized countersunk fastener allows the screw head to sit neatly within the recessed opening, helping maintain a compact and professional installation.

Mechanical mounting is particularly useful in industrial and engineering applications where adhesive bonding alone is not preferred or where the magnet may need to be removed or replaced.

Care is required during installation because Samarium Cobalt is a hard but brittle material. Do not overtighten the fixing screw or subject the magnet to excessive mechanical stress.

Why Choose a Samarium Cobalt Magnet?

Samarium Cobalt magnets belong to the rare earth magnet family and combine strong permanent magnetic performance with excellent environmental and thermal stability.

SmCo magnets are particularly valued for their:

• Excellent performance at elevated temperatures
• Strong resistance to irreversible demagnetisation
• Good natural corrosion resistance
• Excellent magnetic stability
• Strong rare earth magnetic performance
• Suitability for demanding industrial environments

These characteristics make SmCo magnets an excellent option where temperature resistance, stability and long-term magnetic reliability are more important than simply achieving the highest possible magnetic strength.

Technical Specifications

• Product Type: Samarium Cobalt Countersunk Ring Magnet
• Magnetic Material: Samarium Cobalt (SmCo)
• Magnet Type: Rare Earth Permanent Magnet
• Shape: Ring / Countersunk
• Outside Diameter: 20mm
• Height: 10mm
• Countersunk Hole Diameter: 5.2mm
• Polarity: South pole on countersunk face
• Mounting Method: Compatible countersunk fastener
• Typical Applications: High-temperature equipment, sensing, positioning, industrial machinery and precision magnetic assemblies

High-Temperature and Industrial Applications

The combination of SmCo magnetic material, 20mm x 10mm dimensions, defined South-pole orientation and countersunk mounting makes this magnet particularly useful for specialised engineering applications.

Samarium Cobalt magnets are commonly selected for equipment operating in environments where conventional magnetic materials may experience performance limitations due to elevated temperatures or demanding operating conditions.

Potential uses include motors, sensors, actuators, instrumentation, aerospace systems, industrial machinery and specialised electronic equipment.

Pairing North and South Countersunk Magnets

Where two countersunk magnets are being used together, polarity is an important consideration.

This model has the South pole on the countersunk face. For a magnet-to-magnet installation, it can be paired in the appropriate orientation with a corresponding North-pole countersunk magnet, as opposite magnetic poles attract.

Using defined-polarity magnets allows designers and engineers to create predictable magnetic attraction or repulsion within custom assemblies.

Please Note

Samarium Cobalt magnets are hard and brittle. They can chip, crack or fracture if dropped, struck, overtightened or allowed to collide forcefully with another magnet or steel surface.

When installing through the countersunk hole, select an appropriately sized fastener and tighten carefully. The screw should secure the magnet without placing excessive pressure on the countersunk surface.

Actual magnetic holding performance depends on factors including mating material, steel thickness, contact area, air gaps, operating temperature and direction of applied force.

The South pole is located on the countersunk face, so polarity must be considered when combining this magnet with other permanent magnets or polarity-sensitive components.

Do not drill, cut or machine the magnet. Keep strong magnets away from children, pacemakers, medical implants, magnetic storage media and sensitive electronic equipment.