Neodymium Disc Magnet – 5mm x 4mm

The Neodymium Disc Magnet – 5mm x 4mm is a compact rare earth permanent magnet measuring 5mm in diameter x 4mm thick. Manufactured from Neodymium Iron Boron (NdFeB), this small cylindrical disc magnet provides high magnetic performance relative to its physical size and is suitable for product assemblies, engineering, manufacturing, sensors, magnetic closures, models, prototypes and custom OEM applications.

With a diameter of just 5mm and a relatively substantial 4mm thickness, this magnet has a compact, near-cylindrical profile that can be incorporated into small circular recesses, housings and precision assemblies where installation space is limited.

Also known as a 5mm neodymium disc magnet, rare earth disc magnet, NdFeB disc magnet, small round neodymium magnet or permanent disc magnet, it provides continuous magnetic attraction without electricity, batteries or charging.

Key Features

• Diameter: 5mm
• Thickness: 4mm
• Material: Neodymium Iron Boron (NdFeB)
• Compact disc / cylindrical shape
• Rare earth permanent magnet
• High magnetic performance relative to size
• Suitable for small circular recesses and housings
• Suitable for product assemblies
• Useful for magnetic closures and catches
• Suitable for sensors and instrumentation
• Useful for models and prototypes
• Permanent magnetic operation
• No electricity, batteries or charging required
• Suitable for engineering and OEM applications

Common Applications

• Product assemblies
• Engineering
• Manufacturing
• Small magnetic closures
• Magnetic catches
• Sensors and instrumentation
• Position detection
• Models and miniatures
• Electronics assemblies
• Fixtures
• Displays
• Research and development
• Laboratory equipment
• Prototypes
• Custom magnetic assemblies
• OEM products

5mm Diameter x 4mm Thick Neodymium Magnet

This neodymium magnet measures 5mm in diameter x 4mm thick, giving it a compact profile suitable for applications where both diameter and installation space are restricted.

Its dimensions can make it useful for integration into:

• Small circular recesses
• Product housings
• Mechanical assemblies
• Sensors
• Models
• Magnetic closures
• Prototype equipment
• Custom manufactured products

Where installed into a recess, provide appropriate dimensional clearance and avoid force-fitting the brittle neodymium material.

Neodymium Iron Boron Rare Earth Magnet

Neodymium Iron Boron (NdFeB) is a high-performance rare earth permanent magnetic material commonly used where strong magnetic properties are required from compact dimensions.

Small neodymium magnets are widely incorporated into:

• Manufactured products
• Sensors
• Electronics
• Closures
• Mechanical assemblies
• Models
• Instruments
• Prototype devices

The specific neodymium grade has not been supplied for this magnet and should not be assumed.

Small Product Assemblies

The compact 5mm x 4mm size makes this disc magnet useful for appropriately designed products where a larger magnet may be impractical.

Potential applications include:

• Small enclosures
• Removable components
• Magnetic catches
• Positioning systems
• Models
• Instruments
• Prototype products
• Custom assemblies

Depending on the application, the magnet may attract suitable ferromagnetic steel or another appropriately oriented permanent magnet.

Magnetic Closures and Catches

Small neodymium disc magnets can be incorporated into compact magnetic closure systems.

Potential applications include:

• Small boxes
• Product enclosures
• Display components
• Models
• Packaging
• Removable covers
• Custom products

The magnet may be paired with compatible ferromagnetic steel or another permanent magnet.

For magnet-to-magnet closures, confirm polarity and orientation before permanently bonding the magnets into position.

Sensors and Instrumentation

The small dimensions of this neodymium disc magnet can make it useful for appropriately designed magnetic sensing systems.

Potential applications include:

• Position sensing
• Proximity detection
• Reed switches
• Magnetic switches
• Instrumentation
• Automation equipment
• Electronic prototypes

The magnetisation direction and pole orientation have not been supplied. Where magnetic field direction is important, confirm the required specification before installation.

Magnetisation Direction

Disc magnets can be manufactured with different magnetisation configurations.

The magnetisation direction for this product has not been supplied.

Do not automatically assume that the two 5mm circular faces correspond to the north and south magnetic poles.

For sensor applications, magnet-to-magnet assemblies and engineered magnetic circuits, polarity and magnetisation direction should be confirmed before permanent installation.

Magnetic Performance

Actual magnetic performance depends on factors including:

• Neodymium grade
• Magnetisation direction
• Magnet geometry
• Magnetic circuit design
• Target steel composition
• Target steel thickness
• Available contact area
• Surface condition
• Air gaps
• Paint and coatings
• Load direction

No specific pull force or magnetic flux density in Gauss has been supplied for this magnet and these values should not be inferred from its dimensions.

Direct Pull vs Shear Force

Magnetic holding performance varies according to the direction of the applied load.

Direct pull occurs when the magnet is pulled perpendicular to a compatible steel surface.

Shear force occurs when the load acts parallel to the target surface and encourages the magnet to slide.

Practical holding in shear can be substantially lower than ideal direct-pull performance and depends heavily on surface friction and installation geometry.

Air Gaps and Surface Contact

Small neodymium magnets perform best when positioned close to compatible ferromagnetic material.

Magnetic attraction can be reduced by gaps created by:

• Paint
• Powder coating
• Adhesive
• Plastic
• Protective films
• Dirt
• Rust
• Uneven surfaces
• Mechanical clearance

Because this magnet is only 5mm in diameter, even relatively small air gaps can significantly affect practical magnetic performance.

Bonding Neodymium Disc Magnets

This magnet may be bonded into a suitable circular recess or onto an appropriate substrate.

Before bonding:

• Confirm magnetic polarity and orientation
• Clean and dry the surfaces
• Remove oil, grease and contamination
• Select an adhesive compatible with both materials
• Provide appropriate dimensional clearance
• Avoid force-fitting
• Allow the adhesive to cure according to its instructions

The specific coating or plating has not been supplied, so adhesive compatibility should be confirmed for the actual magnet surface.

Do not drill or machine the magnet to create a mounting feature.

Compatible Target Materials

Neodymium magnets attract suitable ferromagnetic materials, including:

• Mild steel
• Iron
• Magnetic steel
• Compatible ferromagnetic components

They do not effectively attract non-magnetic materials such as:

• Aluminium
• Copper
• Brass
• Plastic
• Timber
• Glass

Many stainless steel grades may be weakly magnetic or non-magnetic and should be tested before relying on magnetic attraction.

Neodymium vs Ferrite Magnets

Neodymium and ferrite are both permanent magnetic materials but provide different characteristics.

Neodymium magnets generally offer:

• Higher magnetic performance relative to physical size
• Strong magnetic properties from compact dimensions
• Advantages for miniature and space-constrained applications
• Broad use in engineering, sensing and manufactured products

Ferrite magnets are generally:

• More economical
• Naturally corrosion resistant
• Suitable for many general-purpose applications
• Useful where larger physical dimensions are acceptable

For a small magnet measuring only 5mm x 4mm, neodymium can be particularly useful where magnetic performance relative to available space is important.

Permanent Magnetic Operation

This neodymium disc magnet is a permanent magnet.

It requires:

• No electricity
• No batteries
• No charging
• No external power supply

Its magnetic field remains continuously active during normal use.

Technical Specifications

• Product Type: Neodymium Disc Magnet
• Alternative Names: Rare Earth Disc Magnet, NdFeB Disc Magnet, Round Neodymium Magnet, Small Neodymium Magnet
• Diameter: 5mm
• Thickness: 4mm
• Shape: Disc / Cylinder
• Magnetic Material: Neodymium Iron Boron (NdFeB)
• Magnet Type: Rare Earth Permanent Magnet
• Magnetic Operation: Permanent
• Power Required: None
• Target Materials: Compatible ferromagnetic iron and steel
• Primary Functions: Magnetic attraction, closure, positioning, sensing and product integration
• Typical Applications: Product assemblies, engineering, manufacturing, sensors, closures, models, prototypes and OEM products

Handling Small Neodymium Magnets

Neodymium magnets are hard and brittle despite their high magnetic performance.

Avoid:

• Allowing magnets to snap together
• Allowing magnets to strike steel objects
• Dropping them onto hard surfaces
• Force-fitting magnets into undersized recesses
• Drilling
• Cutting
• Grinding
• Machining

Neodymium magnets can chip, crack or fragment during uncontrolled collisions.

Because of the magnet's small size, take particular care when handling multiple pieces, as they can attract each other suddenly and may be difficult to separate.

Safety Information

This 5mm x 4mm neodymium magnet presents a serious ingestion hazard and must be kept securely away from babies and children.

If multiple magnets are swallowed, or a magnet is swallowed with another metal object, they can attract through intestinal tissue and cause severe or life-threatening injuries. Seek urgent medical attention if magnet ingestion is suspected.

Keep neodymium magnets an appropriate distance from:

• Pacemakers
• Implanted medical devices
• Magnetic storage media
• Magnetic cards
• Sensitive electronic equipment

If incorporated into a consumer product, model or other assembly, ensure the magnet is securely retained so that it cannot become detached during normal use.

Please Note

This product is a Neodymium Disc Magnet measuring 5mm in diameter x 4mm thick, manufactured from Neodymium Iron Boron (NdFeB) rare earth magnetic material.

No specific neodymium grade, pull force, Gauss rating, coating or plating, magnetisation direction, pole orientation, dimensional tolerance or maximum operating temperature has been supplied and these specifications should not be assumed.

Actual magnetic performance depends on magnetic grade, magnetisation, target steel composition and thickness, available contact area, air gaps, surface condition, magnetic circuit and operating conditions.

The stated 5mm x 4mm dimensions describe the physical size of the magnet and do not represent its pull force, lifting capacity or safe working load.

This magnet is not certified lifting equipment and should not be used for overhead or safety-critical lifting.