Neodymium Disc Magnet – 12mm (D) x 3mm (H) | N42

The Neodymium Disc Magnet – 12mm (D) x 3mm (H) | N42 is a compact rare earth permanent magnet measuring 12mm in diameter x 3mm thick. Manufactured from N42 grade Neodymium Iron Boron (NdFeB), this low-profile round magnet provides high magnetic performance relative to its size and is suitable for product assemblies, magnetic closures, displays, sensors, electronics, engineering, craft, prototypes and custom OEM applications.

Also known as an N42 disc magnet, rare earth disc magnet, neodymium round magnet, NdFeB disc magnet or 12mm neodymium magnet, its slim 3mm profile makes it particularly useful where installation depth is limited. The flat circular geometry allows the magnet to be incorporated into recessed housings, bonded assemblies and compact magnetic mechanisms.

As a permanent magnet, this N42 neodymium disc requires no electricity, batteries or charging to maintain its magnetic field.

Key Features

• 12mm diameter
• 3mm thickness
• N42 magnetic grade
• Neodymium Iron Boron (NdFeB)
• Rare earth permanent magnet
• Compact, low-profile disc shape
• High magnetic performance relative to size
• Suitable for shallow recesses and compact assemblies
• Useful for magnetic closures and positioning
• Suitable for sensors and instrumentation
• Suitable for displays, models and prototypes
• Permanent magnetic operation
• No electricity or batteries required
• Suitable for custom and OEM applications

Common Applications

• Magnetic closures
• Product assemblies
• Engineering projects
• Sensors and switches
• Electronics
• Instrumentation
• Displays and signage
• Furniture and cabinetry
• Models and miniatures
• Craft and DIY projects
• Fixtures and positioning
• Prototypes
• Research and development
• Custom magnetic assemblies
• OEM manufacturing

12mm Diameter x 3mm Thick Neodymium Disc Magnet

This N42 neodymium magnet measures:

• Diameter: 12mm
• Thickness: 3mm

Its 12mm circular footprint combined with a slim 3mm thickness creates a compact magnetic component suitable for applications where available installation depth is limited.

Potential installation locations include:

• Circular recesses
• Product housings
• Furniture components
• Display assemblies
• Sensor systems
• Prototype devices
• Magnetic closures
• Custom manufactured products

The dimensions describe the physical size of the magnet and should not be interpreted as a pull-force or load-capacity rating.

N42 Grade Neodymium Magnet

This disc magnet is manufactured from N42 grade Neodymium Iron Boron.

N42 is a recognised neodymium magnetic material grade and describes characteristics of the magnetic material itself. It does not mean that every N42 magnet provides the same pull force.

The practical performance of a finished N42 magnet also depends on factors including:

• Magnet dimensions
• Magnet shape
• Magnetisation direction
• Magnetic circuit
• Target steel
• Contact area
• Air gaps
• Load direction
• Installation geometry

For this reason, the N42 grade should not be interpreted as a pull-force or safe working load rating.

Neodymium Iron Boron Rare Earth Material

Neodymium Iron Boron (NdFeB) is a high-performance rare earth permanent magnetic material.

Compared with many conventional permanent magnetic materials, neodymium can provide substantial magnetic performance from relatively compact dimensions.

This makes small NdFeB magnets particularly useful in products where:

• Installation space is limited
• Low-profile magnetic components are required
• Compact magnetic mechanisms are being designed
• Strong magnetic performance relative to size is desirable

The specific coating or plating applied to this magnet has not been supplied and should not be assumed.

Low-Profile Magnetic Applications

At only 3mm thick, this neodymium disc magnet is well suited to shallow installations.

Potential uses include:

• Thin product housings
• Recessed magnetic closures
• Display components
• Furniture fittings
• Removable panels
• Packaging
• Models
• Prototype assemblies

When designing a recess, allow suitable clearance rather than attempting to force-fit the magnet.

Neodymium is a hard and brittle magnetic material and can chip, crack or fracture under excessive mechanical stress.

Magnetic Closures

The compact disc shape makes this N42 magnet suitable for integration into magnetic closure systems.

Potential applications include:

• Boxes
• Cabinets
• Cupboards
• Furniture
• Product enclosures
• Removable covers
• Display components
• Custom products

A magnet may attract either another correctly oriented magnet or a suitable ferromagnetic steel target.

When using magnet-to-magnet closures, confirm the magnetic pole orientation before permanently bonding the magnets into place.

Sensors and Instrumentation

Compact neodymium magnets are commonly incorporated into suitable magnetic sensing systems.

Potential applications include:

• Position sensing
• Proximity detection
• Magnetic switches
• Reed switch activation
• Instrumentation
• Automation
• Prototype electronics

Sensor performance depends on the magnetic field, magnetisation direction, distance, orientation and sensitivity of the selected sensor.

The magnetisation direction of this product has not been supplied and should be confirmed where pole orientation is critical.

Magnetisation Direction

The magnetisation direction of this 12mm x 3mm disc magnet has not been supplied.

Disc magnets are commonly available in different magnetic configurations, so the location of the north and south poles should not be inferred solely from the disc shape.

Magnetisation direction affects:

• Pole location
• Working face orientation
• Sensor response
• Magnet-to-magnet interaction
• Holding performance
• Magnetic circuit design

Where magnetic orientation is important, confirm the magnetisation configuration before installation.

Magnetic Holding Performance

Actual magnetic holding performance depends on the complete application.

Important factors include:

• N42 magnetic material
• Magnetisation direction
• Target steel composition
• Target steel thickness
• Available contact area
• Surface flatness
• Air gaps
• Paint or coatings
• Magnet orientation
• Load direction
• Mechanical leverage

No specific pull force or magnetic flux density in Gauss has been supplied for this product and these values should not be inferred solely from its dimensions or N42 grade.

Direct Pull vs Shear Force

Magnetic holding strength can vary significantly depending on the direction in which the load is applied.

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

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

Practical vertical holding can therefore be significantly lower than an ideal direct-pull result.

Vibration, shock and leverage can further reduce practical holding performance.

Air Gaps and Surface Condition

Neodymium magnets generally perform best when positioned close to suitable ferromagnetic steel.

Even small non-magnetic gaps can reduce attraction.

Potential air gaps can be created by:

• Paint
• Powder coating
• Adhesive
• Plastic
• Protective coatings
• Dirt
• Rust
• Uneven surfaces

Because this magnet is relatively compact, minimising unnecessary separation can be particularly important when designing the finished assembly.

Bonding a Neodymium Disc Magnet

The flat circular surfaces make this magnet suitable for bonding into compatible housings and recesses.

For adhesive installation:

• Clean the magnet and substrate
• Remove grease, dust and contamination
• Select an adhesive compatible with both surfaces
• Follow the adhesive manufacturer's instructions
• Avoid unnecessarily thick adhesive layers
• Allow the adhesive to cure fully
• Avoid force-fitting the magnet into an undersized recess

Do not drill, cut or machine the finished neodymium magnet to modify its dimensions.

Compatible Target Materials

Neodymium magnets attract ferromagnetic iron and compatible steels.

Suitable target materials can include:

• Mild steel
• Iron
• Magnetic steel
• Ferromagnetic fasteners
• Compatible steel components

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

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

Many stainless steel grades are also weakly magnetic or non-magnetic and should be tested before use.

Neodymium vs Ferrite Disc Magnets

Neodymium and ferrite are both permanent magnetic materials, but they offer different characteristics.

N42 neodymium magnets generally provide:

• Higher magnetic performance relative to size
• Compact magnetic solutions
• Suitability for space-restricted assemblies
• Strong performance from relatively small dimensions

Ferrite magnets generally provide:

• More economical magnetic performance
• Good natural corrosion resistance
• Good resistance to demagnetisation
• Suitability for many general-purpose applications

Neodymium is commonly selected where high magnetic performance from a compact magnet is a key design requirement.

Permanent Magnetic Operation

This N42 neodymium disc is a permanent magnet.

It requires:

• No electricity
• No batteries
• No charging
• No external power source

Its magnetic field remains continuously active during normal use.

Technical Specifications

• Product Type: Neodymium Disc Magnet
• Alternative Names: N42 Disc Magnet, Rare Earth Disc Magnet, NdFeB Disc Magnet, Round Neodymium Magnet, 12mm Neodymium Magnet
• Diameter: 12mm
• Thickness / Height: 3mm
• Shape: Disc / Round
• Magnetic Material: Neodymium Iron Boron (NdFeB)
• Magnetic Grade: N42
• Magnet Type: Rare Earth Permanent Magnet
• Magnetic Operation: Permanent
• Power Required: None
• Target Materials: Compatible ferromagnetic iron and steel
• Primary Functions: Magnetic attraction, holding, positioning and integration into compact assemblies
• Typical Applications: Closures, sensors, electronics, displays, furniture, engineering, models, prototypes and OEM products

Handling Neodymium Magnets

Neodymium magnets provide high magnetic performance but are also hard and brittle.

Avoid:

• Allowing magnets to snap together forcefully
• Dropping them onto hard surfaces
• Applying bending or leverage
• Force-fitting into undersized recesses
• Drilling
• Cutting
• Machining

Forceful collisions can cause a neodymium magnet to chip, crack or fracture, and broken fragments may have sharp edges.

Safety Information

This 12mm x 3mm neodymium magnet is small enough to present a serious ingestion hazard.

Keep it securely away from babies and children. If multiple strong magnets are swallowed, they can attract to each other through internal tissue and cause severe or potentially life-threatening injuries. Seek urgent medical attention if magnet ingestion is suspected.

Strong magnets should also be kept an appropriate distance from:

• Pacemakers and other implanted medical devices
• Magnetic storage media
• Magnetic cards
• Sensitive electronic equipment
• Devices that may be affected by magnetic fields

Please Note

This product is a Neodymium Disc Magnet measuring 12mm in diameter x 3mm thick and manufactured from N42 grade Neodymium Iron Boron (NdFeB).

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

The N42 grade identifies the magnetic material grade and does not represent the finished magnet's pull force, holding capacity or safe working load.

Actual magnetic performance depends on magnetisation direction, target steel thickness and composition, available contact area, air gaps, surface condition, magnet orientation and load direction.

Neodymium is a hard and brittle magnetic material. Avoid drilling, cutting, machining, force-fitting and uncontrolled collisions.

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