Neodymium Block Magnet – 20mm x 12.5mm x 4.6mm

The Neodymium Block Magnet – 20mm x 12.5mm x 4.6mm is a compact, high-performance rare earth permanent magnet measuring 20mm long x 12.5mm wide x 4.6mm thick. Manufactured from Neodymium Iron Boron (NdFeB), this rectangular magnet provides strong magnetic performance relative to its size and is suitable for industrial, engineering, manufacturing, holding, positioning, closures, displays and OEM applications.

Also known as a rare earth block magnet, rectangular neodymium magnet, NdFeB block magnet or neodymium bar magnet, its flat rectangular profile makes it convenient for integration into equipment, product housings, fixtures, furniture, signage, prototypes and custom magnetic assemblies.

As a permanent magnet, this 20mm x 12.5mm x 4.6mm neodymium block requires no electricity, batteries or charging to maintain its magnetic field.

Key Features

• 20mm length x 12.5mm width x 4.6mm thickness
• Neodymium Iron Boron (NdFeB)
• High-performance rare earth permanent magnet
• Compact rectangular block shape
• Flat profile for integration into products and assemblies
• Strong magnetic performance relative to physical size
• Suitable for holding and positioning
• Useful for magnetic closures and fixtures
• Suitable for bonding into compatible recesses
• Permanent magnetic operation
• No electricity or batteries required
• Suitable for industrial, custom and OEM applications

Common Applications

• Industrial equipment
• Engineering assemblies
• Magnetic holding and positioning
• Product manufacturing
• Magnetic closures
• Furniture and cabinetry
• Displays and signage
• Fixtures and jigs
• Sensors and prototypes
• Craft and DIY projects
• Research and development
• Custom magnetic assemblies
• OEM products

Compact 20mm x 12.5mm x 4.6mm Block Magnet

This neodymium magnet measures 20mm long x 12.5mm wide x 4.6mm thick, providing a compact rectangular magnetic component for applications where a flat magnetic profile is required.

Its geometry can make it useful for integration into:

• Rectangular recesses
• Product housings
• Furniture
• Cabinetry
• Display components
• Mechanical fixtures
• Closures
• Custom manufactured products

The 20mm x 12.5mm x 4.6mm dimensions describe the physical size of the magnet and should not be interpreted as a pull-force or load-capacity rating.

Neodymium Iron Boron Rare Earth Magnet

Neodymium Iron Boron (NdFeB) is one of the strongest commercially available permanent magnet materials and is widely used where high magnetic performance is required within compact dimensions.

Neodymium magnets are commonly incorporated into:

• Industrial machinery
• Magnetic fixtures
• Sensors
• Equipment
• Furniture
• Displays
• Consumer products
• Engineering systems

The specific NdFeB magnetic grade of this magnet has not been supplied and should not be assumed.

Rectangular Magnet for Holding and Positioning

The rectangular shape provides broad flat surfaces that can be useful for holding, positioning and locating components within an assembly.

Potential applications include:

• Magnetic catches
• Removable panels
• Product closures
• Locating components
• Display fixtures
• Assembly jigs
• Furniture components
• Custom magnetic connections

The suitability of the magnet depends on the required magnetic performance, target material and mechanical design of the complete application.

Magnetisation Direction

The magnetisation direction of this 20mm x 12.5mm x 4.6mm block magnet has not been supplied.

Block magnets can be manufactured with different magnetic pole orientations. The magnetisation direction determines which faces act as the principal magnetic poles and can significantly affect performance within a magnetic circuit.

Where pole orientation is important for sensors, magnetic coupling, attraction or interaction with other magnets, the magnetisation direction should be confirmed before installation.

Magnetic Holding Performance

Actual magnetic performance depends on multiple factors, including:

• Magnetic grade
• Magnetisation direction
• Target steel thickness
• Steel composition
• Available contact area
• Surface flatness
• Air gaps
• Paint and coatings
• Adhesive layers
• Magnet orientation
• Load direction
• Magnetic circuit design

No specific pull force or Gauss rating has been supplied for this magnet and these values should not be inferred solely from its dimensions.

Direct Pull vs Shear Force

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

Direct pull occurs when force attempts to separate the magnet perpendicular to the steel target.

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

A magnet's practical vertical or sideways holding capacity may therefore be substantially lower than its ideal direct-pull performance.

This distinction is particularly important for magnetic mounting, signage, furniture and fixture applications.

Magnetic Attraction Decreases with Distance

Magnetic attraction decreases rapidly as the distance between a neodymium magnet and its ferromagnetic target increases.

Layers that can create an air gap include:

• Paint
• Adhesive
• Plastic
• Paper
• Fabric
• Protective coatings
• Dirt
• Surface irregularities

For strongest practical attraction, maximise close contact with clean, flat and sufficiently thick ferromagnetic steel.

Bonding Neodymium Block Magnets

The flat surfaces of this rectangular magnet make it suitable for bonding into compatible products, housings and recesses.

Potential bonded applications include:

• Furniture
• Cabinetry
• Magnetic closures
• Displays
• Signage
• Product housings
• Fixtures
• Prototypes

Before bonding:

• Clean the magnet and substrate
• Select an adhesive compatible with both surfaces
• Follow the adhesive manufacturer's preparation instructions
• Avoid curing conditions that could exceed the magnet's temperature limits
• Allow the adhesive to cure fully before loading the assembly

Avoid force-fitting the magnet into an undersized recess, as neodymium magnetic material is brittle.

Compatible Target Materials

Neodymium magnets attract ferromagnetic iron and compatible steels.

Suitable target materials may include:

• Mild steel
• Iron
• Magnetic steel sheet
• Ferromagnetic brackets
• Compatible steel machinery components

They will not effectively attract:

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

Many stainless steel grades may also provide weak or negligible magnetic attraction and should be tested before use.

Neodymium vs Ferrite Block Magnets

Both neodymium and ferrite are common permanent magnetic materials, but they offer different performance characteristics.

Neodymium magnets generally provide:

• Much higher magnetic strength relative to size
• Compact dimensions for high-performance applications
• Strong magnetic attraction from relatively small magnet volumes

Ferrite magnets are generally:

• More economical
• Naturally corrosion resistant
• Less powerful relative to their size
• Suitable for many general-purpose applications

Neodymium is typically selected where stronger magnetic performance is required within limited installation space.

Permanent Magnetic Operation

This NdFeB block is a permanent magnet, requiring no external power source to maintain its magnetic field.

It requires:

• No electricity
• No batteries
• No charging
• No electrical wiring

Its magnetic field remains continuously active during normal use.

Technical Specifications

• Product Type: Neodymium Block Magnet
• Alternative Names: Rare Earth Block Magnet, NdFeB Block Magnet, Rectangular Neodymium Magnet, Neodymium Bar Magnet
• Length: 20mm
• Width: 12.5mm
• Thickness: 4.6mm
• Shape: Block / Rectangular
• Magnetic Material: Neodymium Iron Boron (NdFeB)
• Magnet Type: Rare Earth Permanent Magnet
• Magnetic Operation: Permanent
• Power Required: None
• Target Material: Compatible ferromagnetic iron and steel
• Primary Functions: Magnetic holding, positioning and integration into magnetic assemblies
• Typical Applications: Industrial equipment, manufacturing, fixtures, closures, displays, furniture and OEM products

Industrial, Manufacturing and OEM Applications

The combination of a 20mm x 12.5mm footprint and 4.6mm thickness makes this neodymium block magnet suitable for incorporation into a broad range of manufactured products and engineered assemblies.

Potential users include:

• Engineers
• Product designers
• Equipment manufacturers
• Furniture manufacturers
• Display manufacturers
• Fabricators
• Prototype developers
• OEM manufacturers

For technical applications, magnetic performance should be assessed as part of the complete magnetic circuit and mechanical assembly.

Handling Neodymium Block Magnets

Neodymium magnets can generate strong attraction and should be handled carefully.

NdFeB magnetic material is hard and brittle and can chip, crack or fracture if magnets:

• Snap forcefully together
• Strike steel surfaces
• Are dropped
• Experience excessive mechanical stress

Do not drill, cut or machine neodymium magnets using conventional methods.

When handling multiple magnets, separate and control them carefully to prevent uncontrolled collisions and pinch injuries.

Please Note

This product is a Neodymium Block Magnet measuring 20mm long x 12.5mm wide x 4.6mm thick.

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

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

Neodymium Iron Boron is a hard and brittle magnetic material. Avoid drilling, cutting, machining, impact and uncontrolled collisions between magnets.

Strong neodymium magnets can create pinch hazards. Keep magnets away from children, pacemakers and other medical implants, magnetic storage media and sensitive electronic equipment.