Neodymium Ring Magnet – 25mm OD x 5mm ID x 10mm H | N35

The Neodymium Ring Magnet – 25mm OD x 5mm ID x 10mm H | N35 is a strong rare earth permanent magnet measuring 25mm outside diameter (OD) x 5mm inside diameter (ID) x 10mm high. Manufactured from N35 grade Neodymium Iron Boron (NdFeB), this annular magnet combines strong magnetic performance relative to its size with a straight 5mm central through-hole for integration into mechanical, engineering and product assemblies.

Its substantial 25mm outside diameter and 10mm height provide a robust ring-shaped magnetic profile, while the 5mm centre opening can provide clearance for appropriately sized pins, rods, shafts, locating features or other mechanical components. This geometry makes the magnet suitable for positioning systems, sensors, fixtures, machinery, product development, research, prototypes and custom OEM magnetic assemblies.

Also known as an N35 neodymium ring magnet, rare earth ring magnet, NdFeB annular magnet, donut magnet, ring-shaped neodymium magnet or rare earth magnet with a central hole, this magnetic component provides permanent magnetic operation without electricity, batteries or charging.

Key Features

• Outside diameter (OD): 25mm
• Inside diameter / hole: 5mm
• Height: 10mm
• Shape: Ring / annular
• Material: Neodymium Iron Boron (NdFeB)
• Magnetic grade: N35
• Magnet type: Rare earth permanent magnet
• Central opening: 5mm straight through-hole
• Strong magnetic performance relative to size
• Substantial 10mm high ring profile
• Suitable for engineering and manufacturing
• Useful for mechanical and product assemblies
• Suitable for positioning and alignment
• Useful for sensors and instrumentation
• Suitable for fixtures and jigs
• Useful for research and prototype development
• Suitable for custom OEM magnetic assemblies
• Permanent magnetic operation
• No electricity, batteries or charging required

Common Applications

• Engineering
• Manufacturing
• Industrial equipment
• Mechanical assemblies
• Product assemblies
• Positioning systems
• Component alignment
• Fixtures and jigs
• Sensors and instrumentation
• Position detection
• Proximity sensing
• Magnetic switching
• Machinery components
• Research and development
• Laboratory equipment
• Prototype devices
• Custom OEM products

25mm OD x 5mm ID x 10mm High Ring Magnet

This N35 neodymium ring magnet measures:

• 25mm outside diameter
• 5mm inside diameter
• 10mm height

The 5mm central opening creates an annular magnetic body that can be integrated around or alongside suitably sized mechanical components.

The relatively substantial 10mm height provides a deeper ring profile than thin washer-style magnets, making this product useful for applications requiring a compact but robust cylindrical ring geometry.

The stated dimensions describe the physical geometry of the magnet and do not represent its pull force, holding capacity or safe working load.

N35 Grade Neodymium Magnet

This ring magnet is manufactured from N35 grade Neodymium Iron Boron.

N35 is a widely used rare earth magnetic grade that provides strong permanent magnetic performance relative to physical size.

N35 magnets can be useful where:

• Strong permanent magnetism is required
• Available installation space is limited
• A compact ring-shaped magnet is required
• A central through-hole is useful for mechanical integration
• Higher magnetic performance than similarly sized ferrite magnets is preferred

The N35 designation identifies the magnetic material grade and should not be interpreted as a 35kg pull force.

What Does N35 Mean?

The N35 grade is a classification of Neodymium Iron Boron magnetic material.

The numerical designation relates to the material's maximum energy product and is used to distinguish between different neodymium grades.

When comparing magnets with the same dimensions, geometry and magnetisation configuration, different grades can provide different levels of magnetic performance.

N35 does not directly specify:

• Pull force
• Surface Gauss
• Safe working load
• Pole orientation
• Magnetisation direction

These depend on the complete magnetic design and application.

5mm Central Through-Hole

This ring magnet features a 5mm diameter straight central hole extending through its 10mm height.

Depending on the finished assembly, this opening may provide clearance for:

• Pins
• Shafts
• Rods
• Locating features
• Tubes
• Mechanical guides
• Product components

The central hole can make the magnet easier to integrate into products where another component needs to pass through the centre of the magnetic assembly.

However, a 5mm hole does not automatically mean the magnet will fit a 5mm shaft, bolt, pin or rod.

Actual compatibility depends on dimensional tolerances and the mechanical clearance required for the application.

Mechanical and Product Assemblies

The combination of a compact outside diameter, substantial height and central through-hole makes this magnet useful for engineered product assemblies.

Potential applications include:

• Equipment components
• Mechanical mechanisms
• Positioning systems
• Alignment devices
• Product housings
• Sensor assemblies
• Prototype machinery
• Custom magnetic devices

The magnet should be appropriately supported within the finished assembly and should not be treated as a structural component.

Sensors and Instrumentation

Neodymium ring magnets can be incorporated into magnetic sensor systems where the magnet's field configuration is compatible with the selected sensor.

Potential applications include:

• Hall-effect sensors
• Reed switches
• Position detection
• Proximity sensing
• Magnetic switching
• Equipment monitoring
• Instrumentation

Sensor performance depends on:

• Magnetisation direction
• Pole orientation
• Magnet-to-sensor distance
• Sensor sensitivity
• Installation geometry
• Surrounding magnetic materials

The magnetisation configuration has not been supplied and should be confirmed where magnetic field direction is important.

Positioning and Alignment

N35 ring magnets can also be incorporated into positioning and alignment systems.

Potential functions include:

• Component locating
• Repeatable positioning
• Magnetic alignment
• Assembly assistance
• Fixture positioning
• Prototype mechanisms

Where multiple magnets are used together, polarity should be confirmed before permanent installation.

Magnetisation Direction

Neodymium ring magnets can be manufactured with different magnetic configurations.

A ring magnet may potentially be:

• Axially magnetised through its 10mm height
• Diametrically magnetised across its diameter
• Radially magnetised
• Multipole magnetised
• Manufactured with another specialised pole arrangement

The actual magnetisation direction and pole configuration have not been supplied for this product and should not be assumed from the ring shape.

Confirm the magnetic orientation where pole location or field direction is important.

Magnetic Coupling Applications

Ring magnets may be incorporated into magnetic coupling systems where the magnetisation configuration and mechanical design are suitable.

Potential applications include:

• Contactless magnetic coupling
• Rotating mechanisms
• Positioning devices
• Alignment systems
• Prototype mechanical assemblies

Coupling performance depends on:

• Magnetisation direction
• Pole arrangement
• N35 material properties
• Magnet spacing
• Number of magnets
• Mechanical geometry

No coupling torque or force should be inferred from the physical dimensions alone.

Magnetic Performance

Although this magnet is confirmed as N35 grade, practical magnetic performance depends on several additional factors.

These include:

• N35 material properties
• Magnetisation direction
• Pole configuration
• Magnetic circuit
• Target steel composition
• Target steel thickness
• Available contact area
• Surface condition
• Air gaps
• Load direction
• Mechanical leverage

No specific pull force or magnetic flux density in Gauss has been supplied.

These values should not be estimated from the N35 grade or physical dimensions alone.

N35 Does Not Mean 35kg Pull Force

The N35 designation does not mean this magnet has a 35kg pull force.

N35 identifies the grade of the NdFeB magnetic material.

Pull force is a separate performance measurement influenced by:

• Magnet dimensions
• Magnetisation
• Target material
• Target thickness
• Contact area
• Air gaps
• Test conditions

Use a verified pull-force specification where holding performance is critical.

Air Gaps and Magnetic Attraction

Even small air gaps can significantly reduce magnetic attraction.

Potential sources of separation include:

• Paint
• Powder coating
• Adhesive
• Plastic
• Protective films
• Product housings
• Dirt
• Rust
• Mechanical clearance

For maximum practical attraction, unnecessary separation between the magnet and magnetic target should generally be minimised.

Direct Pull vs Shear Force

Where this magnet is used against suitable ferromagnetic steel, magnetic holding depends on load direction.

Direct pull occurs when the magnet is separated perpendicular to the target.

Shear loading occurs when the magnet is encouraged to slide parallel to the target.

Shear performance can be influenced by:

• Surface friction
• Contact quality
• Paint and coatings
• Installation orientation
• Air gaps
• Mechanical leverage
• Vibration

Test the completed assembly under realistic conditions where magnetic holding is important.

Target Steel Thickness

The target steel is an important part of any magnetic holding system.

Practical performance can depend on:

• Steel composition
• Steel thickness
• Target dimensions
• Surface condition
• Available contact area
• Magnetic saturation

Very thin steel may not provide the same magnetic response as a suitably thick ferromagnetic target.

Testing against the actual target material is recommended for performance-critical applications.

Bonding a Neodymium Ring Magnet

This N35 ring magnet can be bonded into an appropriately designed housing or product assembly.

Before bonding:

• Confirm the required magnetic orientation
• Confirm polarity where multiple magnets are involved
• Clean both bonding surfaces
• Remove grease, dust and contamination
• Select an adhesive compatible with the magnet's actual surface finish
• Provide suitable 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 with the actual magnet surface should be confirmed.

Avoid Force-Fitting Through the 5mm Hole

Neodymium Iron Boron is hard but brittle.

Do not force an oversized shaft, bolt, pin, rod or other component through the 5mm central opening.

Excessive mechanical pressure may cause:

• Chipping
• Cracking
• Splitting
• Fracturing
• Damage to the surface finish

Provide appropriate mechanical clearance based on the actual dimensions and tolerances of the magnet and mating component.

Do Not Machine Neodymium Magnets

Finished neodymium magnets should not be modified using conventional workshop methods.

Avoid:

• Drilling
• Cutting
• Grinding
• Crushing
• Machining
• Enlarging the central hole

These processes can damage the brittle NdFeB material and any protective surface coating.

If a different inside diameter or overall size is required, select a magnet manufactured to the appropriate dimensions.

Compatible Target Materials

Neodymium magnets attract suitable ferromagnetic materials, including:

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

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

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

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

N35 Neodymium vs Ferrite Ring Magnets

N35 neodymium and ferrite ring magnets provide different characteristics.

N35 neodymium ring magnets generally provide:

• Higher magnetic performance relative to size
• Strong magnetic properties from compact dimensions
• Advantages in space-restricted systems
• Suitability for sensors and engineered assemblies

Ferrite ring magnets generally provide:

• Lower cost
• Good natural corrosion resistance
• Good resistance to demagnetisation
• Suitability where larger dimensions are acceptable

N35 neodymium is commonly selected where strong magnetic performance from a compact ring-shaped permanent magnet is required.

Permanent Magnetic Operation

This N35 neodymium ring 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 Ring Magnet
• Alternative Names: N35 Neodymium Ring Magnet, Rare Earth Ring Magnet, NdFeB Ring Magnet, Neodymium Annular Magnet, Donut Magnet
• Outside Diameter (OD): 25mm
• Inside Diameter / Hole: 5mm
• Height: 10mm
• Central Opening: Straight through-hole
• Shape: Ring / Annular
• Magnetic Material: Neodymium Iron Boron (NdFeB)
• Magnetic Grade: N35
• Magnet Type: Rare Earth Permanent Magnet
• Magnetic Operation: Permanent
• Power Required: None
• Compatible Targets: Suitable ferromagnetic iron and steel
• Primary Functions: Magnetic attraction, positioning, alignment, sensing, coupling and product integration
• Typical Applications: Engineering, manufacturing, mechanical assemblies, sensors, fixtures, machinery, research, prototypes and OEM products

Safety and Handling

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

Keep fingers clear when the magnet approaches another magnet or ferromagnetic object. Sudden attraction can cause:

• Pinching
• Trapping injuries
• Magnet collisions
• Chipping
• Cracking
• Fragmentation

Neodymium is a hard but brittle material, so uncontrolled impacts and excessive mechanical pressure should be avoided.

Ingestion Hazard

Small magnets can present a serious ingestion hazard, particularly if multiple magnets are swallowed.

Keep this magnet securely away from babies and children. If incorporated into another product, ensure the magnet is securely retained so it cannot become loose during normal use.

Seek urgent medical attention if magnet ingestion is suspected.

Permanent magnets should also be kept an appropriate distance from pacemakers, implanted medical devices, magnetic storage media, magnetic cards and sensitive electronic equipment.

Please Note

This product is an N35 Neodymium Ring Magnet measuring 25mm outside diameter (OD) x 5mm inside diameter (ID) x 10mm high, manufactured from Neodymium Iron Boron (NdFeB) rare earth magnetic material.

The N35 designation identifies the magnetic material grade and does not mean the magnet has a 35kg pull force.

The 5mm inside diameter describes the physical size of the central through-hole and does not automatically indicate compatibility with a 5mm shaft, bolt, pin, rod or other component. Appropriate dimensional tolerance and mechanical clearance should be considered.

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

Actual magnetic performance depends on the N35 material properties, magnetisation configuration, magnetic circuit, target material, target steel thickness, available contact area, surface condition, air gaps, load direction and installation geometry.

Neodymium is a hard and brittle magnetic material. Avoid impact, force-fitting, drilling, cutting, grinding or machining.

The stated 25mm OD x 5mm ID x 10mm H dimensions describe the physical geometry of the magnet and do not represent its pull force, holding capacity or safe working load.

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