Neodymium Block Magnet – 20mm x 20mm x 12mm | N42H | Centre Groove | Epoxy Coated | High Temperature

Description

The Neodymium Block Magnet – 20mm x 20mm x 12mm | N42H | Centre Groove | Epoxy Coated | High Temperature is a specialised rare earth magnet designed for industrial, engineering and custom magnetic applications requiring strong magnetic performance, enhanced temperature resistance and a distinctive grooved design.

Manufactured from N42H grade Neodymium Iron Boron (NdFeB), this high-performance rectangular magnet combines powerful magnetic attraction with a high-temperature magnetic material grade. The N42H classification is designed for applications requiring greater resistance to heat-related demagnetisation than standard N42 neodymium magnets.

Measuring 20mm x 20mm x 12mm, this compact neodymium block magnet features a centre groove that may assist with positioning, alignment or integration into compatible custom mounting assemblies. The groove provides a distinctive structural feature for applications where a conventional flat-sided block magnet may not be suitable.

The magnet also features a protective epoxy coating, providing an additional barrier between the neodymium material and the surrounding environment. Epoxy coatings are commonly used on rare earth magnets to help protect against moisture exposure, surface wear and corrosion under suitable operating conditions.

With its combination of N42H magnetic grade, centre-grooved geometry and epoxy-coated finish, this magnet is particularly suited to specialised equipment, magnetic fixtures, industrial machinery, engineering prototypes and custom-designed magnetic assemblies.

Neodymium magnets, also known as rare earth magnets, NdFeB magnets or high-strength permanent magnets, are among the strongest commercially available permanent magnets. Their high magnetic energy density allows substantial magnetic performance from relatively compact dimensions.

The N42H designation identifies both the magnetic material grade and its high-temperature classification. The letter H indicates a high-coercivity grade, commonly associated with a maximum operating temperature of up to approximately 120°C, depending on the specific magnet design, operating environment and magnetic circuit.

The exact operating temperature rating of this finished magnet should be confirmed before use in temperature-sensitive applications.

Also known as a 20mm N42H neodymium block magnet, high-temperature rare earth magnet, epoxy-coated neodymium magnet, grooved NdFeB block magnet or industrial high-temperature permanent magnet, this product provides a versatile solution for specialised magnetic applications.

Key Features

• Dimensions: 20mm x 20mm x 12mm

• Magnet Grade: N42H

• Material: Neodymium Iron Boron (NdFeB)

• Shape: Rectangular Block

• Special Feature: Centre Groove

• Coating: Epoxy

• Temperature Classification: High Temperature (H Grade)

• High magnetic strength relative to size

• Enhanced resistance to heat-related demagnetisation

• Protective epoxy-coated surface

• Compact rectangular design

• Centre groove for specialised mounting or positioning applications

• Suitable for custom magnetic assemblies

• Useful for engineering and industrial equipment

• Permanent magnetic field without electrical power

• Suitable for applications requiring a high-coercivity neodymium grade

Common Applications

This N42H epoxy-coated neodymium block magnet may be suitable for:

• High-temperature magnetic assemblies

• Industrial machinery

• Custom magnetic fixtures

• Engineering projects

• Magnetic positioning systems

• Industrial automation

• Specialised mounting assemblies

• Manufacturing equipment

• Magnetic alignment mechanisms

• Equipment development

• Research and development

• Magnetic coupling systems

• Custom magnetic mechanisms

• Engineering prototypes

• Industrial magnetic components

Application suitability depends on the required magnetic field, operating temperature, groove geometry, mounting arrangement and environmental conditions.

High-Temperature N42H Neodymium Grade

The N42H grade is a high-coercivity neodymium magnetic material designed to provide greater resistance to demagnetisation at elevated temperatures compared with standard N42 magnets.

The N42 portion of the designation identifies the magnetic energy classification, while the H suffix indicates a high-temperature grade.

Benefits of N42H Magnetic Material

Enhanced Temperature Resistance

N42H material is designed to resist irreversible demagnetisation at higher temperatures than standard N42 neodymium material.

Strong Magnetic Performance

N42H magnets retain the high magnetic energy density associated with neodymium rare earth magnets.

Industrial Versatility

Suitable for appropriately designed magnetic assemblies operating in environments where elevated temperatures may be encountered.

Permanent Magnetic Field

Provides magnetic attraction without requiring an electrical power supply.

What Temperature Can N42H Magnets Withstand?

N42H neodymium grades are commonly associated with maximum operating temperatures of approximately 120°C.

However, the actual maximum operating temperature of a finished magnet depends on several factors, including:

• Magnet dimensions

• Magnetisation direction

• Magnetic circuit design

• Operating environment

• External demagnetising fields

• Duration of heat exposure

• Manufacturer specifications

Important: The 120°C figure is a typical material-grade reference, not a verified operating limit for this particular magnet.

For high-temperature applications, confirm the manufacturer's specified maximum operating temperature before installation.

Centre Groove Design

This magnet features a centre groove, distinguishing it from conventional flat-sided neodymium block magnets.

The groove may be useful for custom mounting, positioning or alignment arrangements where a recessed feature is required.

Potential benefits include:

• Integration into compatible mounting systems

• Positioning within custom housings

• Alignment with specially designed components

• Accommodation of compatible retention features

• Use in specialised engineering assemblies

The exact groove dimensions, profile and orientation have not been supplied.

For applications requiring precise mechanical fit, confirm the groove specifications before installation.

Important Mounting Considerations

The centre groove should not be assumed to provide a rated mechanical locking or load-bearing function.

Any mounting or retention system should be designed to account for the magnet's brittleness, magnetic forces and intended operating conditions.

Protective Epoxy Coating

This neodymium block magnet features an epoxy-coated finish.

Neodymium Iron Boron is susceptible to corrosion when exposed to moisture and unsuitable environmental conditions. Protective coatings help reduce direct exposure of the magnetic material to the surrounding environment.

Benefits of Epoxy Coating

• Provides a protective surface barrier

• Helps reduce exposure to moisture

• Supports corrosion protection under suitable conditions

• Provides an additional layer of surface protection

• Suitable for specialised industrial magnetic assemblies

Epoxy coatings can offer useful protection, but their performance depends on coating integrity, thickness, chemical exposure, temperature and operating conditions.

Please Note: The coating's colour, thickness, chemical resistance and maximum service temperature have not been specified.

Epoxy coating does not make the magnet waterproof or suitable for continuous immersion unless specifically rated for those conditions.

Compact 20mm x 20mm x 12mm Design

With dimensions of 20mm x 20mm x 12mm, this magnet features a compact block-shaped profile.

Its relatively small footprint makes it suitable for incorporation into custom magnetic assemblies where space is limited.

Potential applications include:

• Compact industrial fixtures

• Specialised magnetic housings

• Engineering prototypes

• Custom positioning mechanisms

• Industrial equipment components

• Magnetic alignment systems

The centre groove provides an additional geometric feature that may be useful in specialised designs.

Industrial and Engineering Applications

This N42H neodymium block magnet may be incorporated into custom-engineered equipment requiring a combination of magnetic strength, elevated-temperature capability and protective coating.

Potential uses include:

• Custom magnetic assemblies

• Industrial positioning mechanisms

• Specialised equipment

• Manufacturing fixtures

• Engineering prototypes

• Magnetic retention systems

• Research and development

The magnet's suitability should be verified against the intended operating temperature, mechanical loading and magnetic performance requirements.

Magnetic Strength and Holding Performance

The magnetic holding strength of this N42H block magnet depends on several factors, including:

• Magnetic material grade

• Magnet dimensions

• Magnetisation direction

• Groove geometry

• Contact surface area

• Target steel thickness

• Surface condition

• Air gaps

• Operating temperature

• Magnetic circuit configuration

The N42H grade does not indicate a pull force of 42kg.

The actual pull-force rating and surface Gauss of this magnet have not been supplied.

For applications requiring a defined holding force, obtain verified performance data or conduct appropriate testing.

Magnetisation Direction

The magnetisation direction of this specific product has not been supplied.

Rectangular neodymium magnets may be magnetised through their thickness, width or length, depending on the manufacturing configuration.

Magnetisation direction affects:

• North and south pole locations

• Magnetic field distribution

• Holding performance

• Attraction to steel surfaces

• Interaction with other magnets

• Suitability for custom assemblies

For precision applications, confirm the magnetisation direction before installation.

Installation and Mounting Considerations

Correct installation is important for reliable magnetic performance.

General Installation Recommendations

1. Confirm the required magnetic performance.

2. Verify the magnet's dimensions and groove geometry.

3. Confirm the magnetisation direction.

4. Assess the intended operating temperature.

5. Select a suitable mounting or retention method.

6. Protect the epoxy coating from damage.

7. Avoid excessive mechanical pressure.

8. Prevent uncontrolled collisions with steel or other magnets.

9. Test the completed assembly under realistic operating conditions.

Important: Do not drill, cut, grind or machine finished neodymium magnets. They are brittle and machining dust can present a fire hazard.

Suitable Magnetic Surfaces

This neodymium magnet attracts suitable ferromagnetic materials, including:

• Mild steel

• Iron

• Certain magnetic steel alloys

• Compatible ferromagnetic components

It does not magnetically attach to:

• Aluminium

• Copper

• Brass

• Timber

• Plastic

• Glass

• Non-magnetic stainless steel

Some stainless steel grades are magnetic, while others are not.

The magnet may also attract or repel other permanent magnets depending on their pole orientation.

Neodymium Magnet Handling and Durability

Although neodymium magnets provide excellent magnetic strength, they are hard and brittle by nature.

They may chip, crack or shatter if:

• Dropped

• Struck against steel

• Allowed to collide with other magnets

• Subjected to bending forces

• Compressed unevenly

• Forced into tight mounting spaces

The centre groove may introduce areas where mechanical stress is concentrated, depending on its geometry.

Avoid applying excessive force to the grooved section.

The epoxy coating should also be protected against scratches, impacts and abrasion that may expose the underlying magnetic material.

Technical Specifications

Compliance & Safety

Strong Magnetic Field: Neodymium magnets can attract ferromagnetic objects and other magnets suddenly. Handle carefully to avoid injury.

Brittle Material: Rare earth magnets are brittle and may chip, crack or shatter if dropped, struck or allowed to collide.

Pinch Hazard: Keep fingers and skin clear when bringing magnets together or placing them against steel surfaces.

Children: Keep magnets away from children. Swallowing magnets can cause severe internal injuries and requires urgent medical attention.

Medical Devices: Strong magnets may interfere with pacemakers, implanted medical devices and magnetically sensitive equipment. Follow the relevant manufacturer's safety guidance.

Electronic Equipment: Keep magnets away from equipment and media that may be affected by magnetic fields.

Machining: Do not drill, cut or grind finished neodymium magnets.

Temperature: N42H is a high-temperature neodymium grade, but the exact operating limit of this finished magnet must be confirmed before use.

Epoxy Coating: Avoid damaging the protective coating, as exposed neodymium material may be susceptible to corrosion.

Mechanical Stress: Avoid excessive force on the centre groove or other areas of the magnet.

Load-Bearing Applications: Do not use this magnet for overhead lifting, personnel safety or other safety-critical holding applications without appropriate engineering assessment and certification.

Frequently Asked Questions

What are the dimensions of this neodymium block magnet?

The magnet measures 20mm x 20mm x 12mm.

What does N42H mean?

N42H is a high-coercivity neodymium magnetic grade. The N42 designation identifies the magnetic energy classification, while the H suffix indicates enhanced resistance to demagnetisation at elevated temperatures.

Is this a high-temperature neodymium magnet?

Yes. N42H is a high-temperature neodymium grade designed for greater resistance to heat-related demagnetisation than standard N42 material.

What is the maximum operating temperature?

N42H grades are commonly associated with maximum operating temperatures of approximately 120°C. However, the exact operating temperature of this finished magnet has not been verified and should be confirmed before use.

What is the purpose of the centre groove?

The centre groove may assist with positioning, alignment or integration into compatible custom mounting assemblies. Its exact geometry and intended mechanical function have not been specified.

Is this magnet epoxy coated?

Yes. The magnet features a protective epoxy coating.

Does epoxy coating make the magnet waterproof?

Not necessarily. Epoxy provides a protective barrier, but waterproof performance depends on the coating specification, integrity and operating conditions.

What is the pull force of this magnet?

A specific pull-force rating has not been provided. Holding performance depends on the magnetisation direction, contact area and application conditions.

Can this magnet be used in industrial machinery?

It may be suitable for industrial magnetic assemblies and specialised equipment, depending on the required magnetic performance, temperature and mounting arrangement.

Can I drill or modify the centre groove?

No. Finished neodymium magnets should not be drilled, ground or machined because they are brittle and machining dust can present safety hazards.

Will this magnet attract stainless steel?

Some stainless steel grades are magnetic, while others are not. Test the specific stainless steel surface before use.

Can this magnet break?

Yes. Neodymium magnets are brittle and may chip, crack or shatter if subjected to impact or excessive mechanical stress.

Is this magnet suitable for outdoor use?

Outdoor suitability depends on the epoxy coating's environmental resistance and the installation conditions. The exact weather-resistance rating has not been supplied.

Related Products

Customers considering this N42H epoxy-coated neodymium block magnet may also be interested in:

• High-Temperature Neodymium Magnets

• N42H Neodymium Magnets

• Epoxy-Coated Neodymium Magnets

• Neodymium Block Magnets in Other Sizes

• N38 Neodymium Block Magnets

• N42 Neodymium Block Magnets

• N52 Neodymium Block Magnets

• Neodymium Disc Magnets

• Neodymium Cylinder Magnets

• Samarium Cobalt High-Temperature Magnets

• Industrial Rare Earth Magnets

• Custom Magnetic Assemblies

Please Note

This Neodymium Block Magnet – 20mm x 20mm x 12mm | N42H | Centre Groove | Epoxy Coated | High Temperature is manufactured from N42H grade neodymium iron boron magnetic material.

Its dimensions are 20mm x 20mm x 12mm, and it features a centre groove and protective epoxy coating.

N42H is a high-coercivity neodymium grade commonly associated with maximum operating temperatures of approximately 120°C. However, the actual temperature rating of the finished magnet must be confirmed before use.

The exact pull force, surface Gauss, magnetisation direction, groove dimensions, dimensional tolerances and coating specifications have not been supplied.

N42H refers to the magnetic material grade and temperature classification, not a pull-force rating.

Neodymium magnets are brittle by nature and must be handled carefully to prevent chipping, cracking or shattering.

For industrial applications requiring specific temperature resistance, holding force or mechanical fit, confirm the relevant technical specifications and test the magnet in its intended operating conditions.