Neodymium Block Magnet - 25mm x 12.5mm x 3.5mm with D4mm hole | N42
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Neodymium Block Magnet – 25mm x 12.5mm x 3.5mm with D4mm Hole | N42
The Neodymium Block Magnet – 25mm x 12.5mm x 3.5mm with Ø4mm Hole | N42 is a compact yet powerful rare earth mounting magnet designed for applications requiring a secure mechanical fixing combined with exceptional magnetic performance. Manufactured from premium N42 grade neodymium (NdFeB), this permanent magnet delivers impressive holding power for its size while offering a convenient 4mm through-hole for easy installation using screws, bolts, rivets, or other suitable fasteners.
Measuring 25mm long x 12.5mm wide x 3.5mm thick, this rectangular neodymium magnet is ideal for projects where adhesive mounting is not suitable or where a removable, mechanically fastened magnetic solution is preferred. The pre-drilled Ø4mm mounting hole enables quick installation onto timber, steel, aluminium, plastics, and other substrates, making it a versatile choice for manufacturing, cabinetry, automation, retail displays, signage, engineering, and DIY projects.
Constructed from high-performance N42 neodymium, this block magnet provides a significantly stronger magnetic field than ferrite magnets of a similar size. Its compact profile allows it to be integrated into tight spaces while delivering reliable holding, locating, positioning, and fastening performance.
Whether you're building magnetic closures, removable access panels, jigs, fixtures, display systems, cabinet catches, or custom engineering assemblies, the 25mm x 12.5mm x 3.5mm Neodymium Block Magnet with Ø4mm Hole offers a durable, efficient, and easy-to-install magnetic solution.
Key Features
- Premium N42 grade neodymium rare earth magnet
- Dimensions: 25mm x 12.5mm x 3.5mm
- Precision Ø4mm through-hole for mechanical fixing
- High magnetic strength relative to its compact size
- Suitable for screws, bolts, rivets, and custom mounting systems
- Compact rectangular block design
- Permanent magnet requiring no external power source
- Ideal for industrial, commercial, and DIY applications
- Excellent holding and positioning performance
- Long-lasting magnetic strength under normal operating conditions
Common Applications
- Magnetic cabinet catches
- Timber and furniture manufacturing
- Engineering fixtures and jigs
- Industrial automation equipment
- Display and exhibition systems
- Signage installation
- Access panels and removable covers
- Workshop organisation
- Custom magnetic assemblies
- DIY projects and prototypes
Ideal For
- Cabinet makers
- Furniture manufacturers
- Engineers
- Industrial designers
- OEM manufacturers
- Automation specialists
- Sign installers
- Maintenance technicians
- Product developers
- DIY enthusiasts
Why Choose an N42 Neodymium Block Magnet with a Mounting Hole?
Unlike adhesive-backed magnets or standard magnetic blocks, this magnet features a precision-machined Ø4mm mounting hole, allowing it to be securely fixed using mechanical fasteners. This creates a far more robust installation for applications exposed to vibration, repeated use, movement, or higher loads.
The N42 neodymium material provides outstanding magnetic performance while maintaining a slim profile, making it ideal where space is limited but strong magnetic holding is required. Compared to ferrite magnets, neodymium magnets offer substantially greater holding power, allowing smaller magnets to achieve higher performance.
Its versatile rectangular shape makes it suitable for magnetic catches, locating systems, closures, and precision positioning applications across manufacturing, construction, retail, and engineering industries.
Technical Specifications
- Product Type: Neodymium Block Magnet
- Material: Neodymium (NdFeB)
- Magnet Grade: N42
- Shape: Rectangular Block
- Length: 25mm
- Width: 12.5mm
- Thickness: 3.5mm
- Mounting Hole: Ø4mm Through-Hole
- Magnetisation: Axially Magnetised (through the 3.5mm thickness)
- Coating: Nickel (Ni-Cu-Ni)
- Reusable: Yes
- Application: Holding, mounting, positioning, fastening, and magnetic assemblies
Please Note
Neodymium magnets are extremely powerful for their size and should be handled carefully to prevent injury or damage. Magnets can snap together unexpectedly and may chip or crack if allowed to collide.
The stated magnetic performance will vary depending on the thickness and type of the mating steel surface, air gaps, paint, coatings, mounting configuration, and the direction of the applied load.
When installing with screws, avoid overtightening, as excessive pressure may damage the magnet. Where appropriate, use washers and tighten fasteners evenly to distribute the load.
Keep this product away from pacemakers, medical implants, magnetic storage devices, and sensitive electronic equipment. Neodymium magnets are brittle and should not be drilled, cut, machined, or subjected to high impact after manufacture.
Typical Physical Properties
NB: Ranges are indicative for product category, please check individual products for specic values within that range.
Production Flow Diagram
Demagnetization Curves
Surface Treatment
The most common coating for Neodymium magnets is Nickel + Copper + Nickel (Ni + Cu + Ni). This coating offers the magnet relatively good protection from corrosion and passive applications. If the magnet will be exposed to moisture or liquid then consider the use of an organic coating such as Epoxy. A hard wearing coating, Epoxy is suited to applications where the magnet will come under some friction or knocking.
Range and Tolerance
Magnets are readily available in Blocks, Discs, Cylinders & Rings. We specializes in the supply of short-run prototype magnets including Arc Segments, various magnetic orientations etc. If you need a magnet size that we don't carry in stock, submit a Design-a-Magnet enquiry for a quote on your custom magnet design.
Magnetic Properties
Neodymium magnets are offered in several different grades. The first section N30-54 has an operating temperature of up to 80 degrees. Most of our stock only goes up to N38. The second section, denoted with the "M" prefix after the grade has an operating temperature 100 degrees. After this the grades are "H", "SH", "UH" & "EH". In order for the magnet to withstand a higher operating temperature, during production more of the raw material PrNd is incorporated as these elements have a naturally occurring resistance to high temperatures.
Returns Policy
If you are not entirely satisfied with your purchase, we're here to help.
We have a 30 Day Returns policy at Frenergy Magnets. You may return your item within 30 days of receiving it to receive a refund.
The product/s must be unused and in the same condition you received them in. Please contact us at info@frenergy.com.au to initiate the returns process.
The buyer is responsible for the cost of returning the order.
